feat(render): Campaign OVERHAUL S2 chunk 5 + closeout — registry is the only render membership owner

Chunk 5 (consumer cutover): WalkProductionWorldData's per-cell views are
borrowed from ShadowObjectRegistry.GetRetailPartEntriesInCell and resolved
through RenderSceneQuery.TryGetByLocalEntityId; every render-side sweep,
bucket, parent-cell and root-position fallback is deleted (AD-116 for the
one-frame registry→scene window, counted in UnregisteredRenderMembershipCount).
A live entity with visual parts but no collision geometry registers
render-only (LiveEntityCollisionBuilder computes the part array before the
empty-shapes gate).

Closeout fixes found while landing it:
- RefloodOwnerForLandblock forwards the retained part array — a reflood is
  retail's recalc_cross_cells over the SAME CPartArray; without it every owner
  touched by a landblock replacement commit lost its render membership.
- Non-colliding DAT statics register render-only from BOTH publishers
  (LandblockPhysicsPublisher.PublishStaticEntity,
  LandblockPhysicsContentBuilder.RegisterRenderOnlyStatic). The G2 self-gate
  pixel diff caught them vanishing (Facility Hub wall panels): retail floods
  every object regardless of collision (CEnvCell::init_static_objects
  0x0052c350, add_shadows_to_cells 0x00514ae0).
- S2 dual review fix batch (arch + retail lens, lead-verified):
  Suspend clears the retail product (remove_shadows_from_cells 0x00511230 is
  one transaction); AttachChild/DetachChild advance the mutation revision so
  a prepared SetPosition cannot clobber a child's rows; an attached child
  never floods on its own re-registration; RemoveLandblock and the non-rooted
  RetireOwnerFromLandblock prune retail rows (render-only statics end with
  their landblock); a render-only owner's no-cell-array commit republishes at
  its destination cell (AD-117); an empty non-null part array is treated as
  null; per-move closures/LINQ replaced by index loops; EnvCell shells stay
  out of the scene's LocalEntityId index (payload-less records); the index
  predicate compares the id; the dead per-cell scene indices are deleted.

Register: AD-116 (chunk 5), AD-117 (four residual Contract A/B readings).
Evidence: s2-membership-ownership-map.md §8 (chunk 5) and §9 (closeout).

Gates (Release): Core 4,984/4,984; Content 214/214; Runtime 1,884/1,884;
App hermetic lane 6,760/6,760; App InstalledDat lane 217 pass / 1 skip /
2 pre-existing #383 layout-fixture failures; App Windows lane 1/1.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

docs/architecture/acdream-architecture.md

@@ -1103,11 +1103,25 @@ retail's synthetic outdoor cell; the player's current cell separately owns
 sunlight and indoor lighting. A null root exists only for login/debug/streaming-
 gap fallback frames. `RetailPViewRenderer` and `RetailPViewPassExecutor` are
 composition/pass facades, and `PortalVisibilityBuilder` has no production
-caller. This does **not** yet mean the complete world graph has one owner:
-`WalkProductionWorldData` still reconstructs frame buckets from scene records,
-AABBs, and aggregate shadow-owner cells. Campaign OVERHAUL OH3 replaces that
-boundary with one canonical published cell graph and typed render/physics
-membership transaction.
+caller. **Campaign OVERHAUL S2 (chunks 1-5, closed 2026-09-03) gave render
+and physics cross-cell membership one canonical owner:**
+`ShadowObjectRegistry` computes retail's exact CELLARRAY
+(`calc_cross_cells_static`/`add_shadows_to_cells`, Contract A/B) once per
+registration/move transaction and retains it both as collision rows
+(`GetOwnerCells`) and per-cell `RetailPartEntry` render rows
+(`GetRetailPartEntriesInCell`) — one flood drives both, never two
+independent ones. `WalkProductionWorldData` no longer reconstructs
+membership from scene records, prepared visual AABBs, or per-record
+aggregate shadow-owner cells: `GetCellStatics`/`GetCellDynamics`/
+`GetOutdoorStatics`/`GetOutdoorDynamics` are a borrowed, on-demand view over
+the registry's per-cell entries, resolved to a projected record through
+`RenderSceneQuery.TryGetByLocalEntityId`. Portal topology, building
+ownership, and drawable-cell identity remain a separate concern S2
+deliberately left alone (S3's `WalkPView` state consolidates that
+triplication, not this membership graph) — S2 scoped to render/physics
+cross-cell membership only. Full detail:
+`docs/architecture/worldbuilder-inventory.md`'s "Retail static render-shadow
+cell membership" / "Consumer cutover to a borrowed per-cell view" entries.
 
 **Current draw discipline and known non-retail order.** The walk records an
 ordered event stream for landscape cells, building portals, EnvCell shells,

docs/architecture/worldbuilder-inventory.md

@@ -193,19 +193,47 @@ per-entity retail CELLARRAY (`TryGetRetailCellArray`) plus per-cell part
 entries (`GetRetailPartEntriesInCell`) — not two independent floods, and not
 rebuilt per frame. A caller that supplies no part array (only test/legacy
 call sites remain) keeps the pre-chunk-3 collision-only dispatch untouched.
-`WalkProductionWorldData`'s indoor and outdoor static sweeps BORROW the
-retail array whole per record; they no longer recompute membership from each
-MeshRef's prepared visual AABB (the deleted `ResolveStaticRenderCells` /
-`ShadowObjectRegistry.ComputeStaticRenderCells` pair). A structural
-consequence: an object mixing a colliding BSP part with a decorative
-non-BSP part now gets a collision row for its BSP part in every cell the
+**Consumer cutover to a borrowed per-cell view (S2 chunk 5, 2026-09-03).**
+`WalkProductionWorldData`'s three per-frame scene sweeps (indoor static,
+outdoor static, dynamic) and their five per-cell bucket dictionaries are
+deleted. `GetCellStatics`/`GetCellDynamics`/`GetOutdoorStatics`/
+`GetOutdoorDynamics` instead read
+`ShadowObjectRegistry.GetRetailPartEntriesInCell` for the QUERIED cell
+directly — already in retail CELLARRAY-then-part-array insertion order —
+collapse the entries to their distinct owning entity ids (an entity's own
+run of entries for one cell is always contiguous, since the registry
+removes-then-re-adds a whole entity's rows atomically), and resolve each id
+back to its `RenderProjectionRecord` through
+`RenderSceneQuery.TryGetByLocalEntityId` — a new presentation-side index
+`ArchRenderScene` maintains alongside its existing per-cell/per-class
+indices, keyed by the SAME `RenderSourceMetadata.LocalEntityId` the
+registry is keyed by (App-only presentation state, never a second
+membership source). Statics vs. dynamics is the record's own
+`ProjectionClass` (`LiveDynamicRoot`/`EquippedChild` are dynamic; every
+other class, including `ActiveAnimatedStatic`, is static — the same split
+`ArchRenderScene`'s own internal indexing already used); building shells
+are excluded from both — they draw at their own building's shell turn
+(`_shellsByAnchor`, still filled by the ONE surviving narrow sweep, since
+buildings are the landcell building channel, out of S2's scope), never at
+the cell's ordinary object-list turn. A structural consequence carried
+over from chunk 3: an object mixing a colliding BSP part with a decorative
+non-BSP part gets a collision row for its BSP part in every cell the
 combined CELLARRAY reaches, including cells the BSP part alone would not
-have crossed — membership is decided by the whole-part-array flood, not per
-part; the BSP polygon test still decides actual contact at query time. A
-record whose registry entry has no retail array yet (a streaming-window race
-between the static-projection journal and the physics publisher) falls back
-to its authored parent cell alone, counted by
-`WalkProductionWorldData.UnregisteredStaticRenderFallbackCount`.
+have crossed — membership is decided by the whole-part-array flood, not
+per part; the BSP polygon test still decides actual contact at query time.
+An entity the registry HAS flooded into a cell but whose projected record
+the presentation journal has not applied yet this frame (the transient
+race between the physics publisher and the projection journal — AD-116)
+contributes to NO cell for that frame; there is no fallback to an authored
+parent cell or a root-position cell any more (both deleted this chunk),
+matching retail's own rule that an object not yet in a cell is not drawn.
+Every distinct entity id this happens for in one frame is counted once in
+`WalkProductionWorldData.UnregisteredRenderMembershipCount` (renamed from
+`UnregisteredStaticRenderFallbackCount`, which under the pre-chunk-5 model
+also covered the separate dynamic-record fallback) and reported by one
+print-only `[walk-membership]` line — gated on
+`RenderingDiagnostics.ProbeFacilityStairsEnabled`, the walk family's
+existing diagnostic flag — at the start of the next frame when nonzero.
 A primitive-only Setup may reuse its already-authored cylsphere collision
 cell set; BSP-bearing and pure-visual statics use the all-visual-part box
 walk. The Facility Hub stair Setup `0x02000623` is the installed-DAT
@@ -217,13 +245,15 @@ Moving multipart objects follow the sibling retail route rather than their
 authored/feet cell alone: `CPhysicsObj::add_shadows_to_cells` installs every
 `CPartArray` part in every cell of the object's retained `CELLARRAY`, and
 `CPhysicsPart::Draw` stamps each part only after that part passes a cell's
-portal test. `WalkProductionWorldData.ResolveDynamicRenderCells` therefore
-reads `ShadowObjectRegistry.TryGetRetailCellArray` directly for every dynamic
-record — the SAME borrow-not-recompute recipe the static sweeps already use
-— falling back to `GetOwnerCells` (counted by the shared
-`UnregisteredStaticRenderFallbackCount`) only when the registry has not
-registered an array yet, while the walk classifier owns a separate
-projection+part drawn-pass stamp. Retail advances that stamp after
+portal test. `WalkProductionWorldData.GetCellDynamics`/`GetOutdoorDynamics`
+therefore read the SAME per-cell `GetRetailPartEntriesInCell` borrowed view
+the static getters use (S2 chunk 5), filtered to the dynamic
+`ProjectionClass`es — not a per-record `TryGetRetailCellArray` lookup with
+its own fallback any more; an entity the registry has flooded into a cell
+but the presentation scene cannot resolve yet contributes to no cell there,
+counted by the shared `UnregisteredRenderMembershipCount` (AD-116), while
+the walk classifier owns a separate projection+part drawn-pass stamp.
+Retail advances that stamp after
 `LScape::draw` + `FlushAlphaList` and before the interior depth clear
 (`PView::DrawCells` @0x005A4886), so a part may draw once in the landscape
 pass and once again in the post-clear interior-cell pass; acdream re-arms the
@@ -260,9 +290,11 @@ moment an attached projection's `WorldEntity` is registered against its
 accepted parent; `CommitProjectionRemoval` (the withdrawal/unparent/teardown
 funnel) calls `DetachChild`. A nested attachment (a child of a child)
 resolves to the ultimate root by walking the existing attach chain at the
-registry, bounded and cycle-safe — `WalkProductionWorldData` no longer walks
-an accepted-parent chain of its own; it reads the child's own id straight off
-`TryGetRetailCellArray`, identically to any other dynamic record.
+registry, bounded and cycle-safe — `WalkProductionWorldData` never walks an
+accepted-parent chain of its own; a child's part entries surface through the
+SAME per-cell borrowed view (S2 chunk 5) every other dynamic record uses,
+resolved to its own projection via `RenderSceneQuery.TryGetByLocalEntityId`,
+identically to any other dynamic record.
 
 **Slice I3 prepared collision extension (2026-07-25).** At its introduction,
 the package remained format 1 and retained mesh type values 1–3; bake-tool 4

docs/launch-options.md

@@ -337,7 +337,7 @@ issue is closed, the strip was missed; delete both.
 | `ACDREAM_PROBE_CATHEDRAL_SKIP_LOOKIN_SHELL` | Campaign FW exact look-in shell discriminator | full hexadecimal cell id, e.g. `F4180112` | suppresses one exact EnvCell shell only when reached through a building look-in; its ordinary interior-root repaint is unchanged | **Behavior-changing diagnostic**; never use as a production fix | `RenderingDiagnostics.ProbeCathedralSkipLookInShellCellId` |
 | `ACDREAM_PROBE_CATHEDRAL_SKIP_SOUTH_BUILDING_SHELL` | Campaign FW south-building carrier discriminator | `=1` | suppresses only the own exterior shell of the cathedral building anchored at `0xF4180112`; its portal walk, look-in cells, and particles remain live | **Behavior-changing diagnostic**; never use as a production fix | `RenderingDiagnostics.ProbeCathedralSkipSouthBuildingShell` |
 | `ACDREAM_PROBE_CATHEDRAL_SHELL_ORDER` | Campaign FW floating-stair shell-order trace | `=1` | samples the ONE walk's actual replay event order every fifth cathedral frame (`CLEAR`, `SEALS`, punches, marks, and EnvCell shells) and reports render-stamp-deduplicated whole-shell turns for cells `0xF4180104/0106/0107/0112/0113/0114` | print-only; never changes admission, depth state, or draw order | `RenderingDiagnostics.ProbeCathedralShellOrderEnabled` |
-| `ACDREAM_PROBE_FACILITY_STAIRS` | #177 Facility Hub stair probe (committed by the `b3b7d922` investigation checkpoint) | `=1` | traces the classifier admission, ordered-stream append, ring upload, and final indirect draw of the authored stair GfxObj `0x010000DE` and the local-player setup parts in cells `0x8A02015E/015F/01C1`, plus the walk root signature for those cells | print-only; never influences admission, order, or depth state; scheduled for deletion in Campaign OVERHAUL S5 | `RenderingDiagnostics.ProbeFacilityStairsEnabled` (read sites in `RetailPViewRenderer`, `WalkPView`, `WalkProductionWorldData`, `WalkStaticStreamPopulator`, `WbDrawDispatcher.*`) |
+| `ACDREAM_PROBE_FACILITY_STAIRS` | #177 Facility Hub stair probe (committed by the `b3b7d922` investigation checkpoint) | `=1` | traces the classifier admission, ordered-stream append, ring upload, and final indirect draw of the authored stair GfxObj `0x010000DE` and the local-player setup parts in cells `0x8A02015E/015F/01C1`, plus the walk root signature for those cells; Campaign OVERHAUL S2 chunk 5 added a `[walk-membership]` line, printed once at the start of a frame only when `WalkProductionWorldData.UnregisteredRenderMembershipCount` was nonzero the PRIOR frame (an entity the registry flooded into a cell but the presentation scene could not resolve yet that frame) | print-only; never influences admission, order, or depth state; scheduled for deletion in Campaign OVERHAUL S5 | `RenderingDiagnostics.ProbeFacilityStairsEnabled` (read sites in `RetailPViewRenderer`, `WalkPView`, `WalkProductionWorldData`, `WalkStaticStreamPopulator`, `WbDrawDispatcher.*`) |
 | `ACDREAM_PROBE_SEAMDRAW` | #176, "throwaway apparatus" | `"1"`/`"true"`/blank → default #176 Facility Hub cell set (7 fixed hex ids); otherwise comma-separated hex cell-id list | change-deduped + 2 s-heartbeat `[seam-cell]`/`[seam-snap]`/`[seam-ent]`/`[seam-mask]` lines from `EnvCellRenderer.Render` and `WbDrawDispatcher` describing per-instance transforms and resolved light-set identities at target cells | print-only | `RenderingDiagnostics.ProbeSeamDrawEnabled` / `SeamDrawTargetCells` |
 | `ACDREAM_PROBE_STEP_WALK` | a6.p3 issue #98 | `=1` | gates `[step-walk]` lines at select points in the transition sub-step loop and step-down probe (requested vs adjusted offset, sphere positions, contact planes, walkable flags) | print-only; no DebugPanel mirror | `PhysicsDiagnostics.ProbeStepWalkEnabled` |
 | `ACDREAM_PROBE_SWEPT` | phase w stage 0 | `=1` | gates one `[cell-swept]` line per `ResolveWithTransition` call comparing the transition's swept cell vs the legacy static `ResolveCellId` path | print-only | `PhysicsDiagnostics.ProbeSweptEnabled` |

docs/research/2026-09-01-overhaul/s2-membership-ownership-map.md

@@ -37,11 +37,11 @@ One transaction per object (`CPhysicsObj::calc_cross_cells_static`
 | Owner | Inputs | Output | Runs | Consumers |
 |---|---|---|---|---|
 | **Chunk 3 (2026-09-02).** `LandblockPhysicsPublisher.PublishStaticEntity` → `ShadowObjectRegistry.RegisterMultiPart` (`LandblockPhysicsPublisher.cs:930-1079`, `ShadowObjectRegistry.cs`, `RegisterMultiPart`/`Register`/`ComputeContractACellArray`/`PublishRetailCellArray`) | the WHOLE visual part array (`ShadowShapeBuilder.FromStaticRenderParts`, chunk 1b) drives ONE Contract A flood (cylsphere route from the collision shapes' cylinders, else bbox route over the part array); a caller with no part array (every unit-test fixture, `partArray ?? shapes`) keeps the pre-chunk-3 legacy dispatch byte-for-byte | `_entityToCells[id]`/`_cells[cell]` (collision) AND `_retailCellArrays`/`_retailPartEntriesByCell` (render) from the SAME array — the second (redundant) flood chunk 1 left running is deleted | once per static at publication | physics broadphase `TransitionTypes.FindObjCollisionsInCell` (`TransitionTypes.cs:3755-3779`); `WalkProductionWorldData` (below) |
-| **DELETED (chunk 2).** Was `WalkProductionWorldData.ResolveStaticRenderCells` → `ShadowObjectRegistry.ComputeStaticRenderCells`. Now: `WalkProductionWorldData.ResolveIndoorStaticRenderCells`/`ResolveOutdoorStaticRenderCells` → `ShadowObjectRegistry.TryGetRetailCellArray` (`WalkProductionWorldData.cs`, `ShadowObjectRegistry.cs:634-663`) | none (borrowed) | chunk 1's retained per-entity retail CELLARRAY, now the SAME array chunk 3 also uses for collision | every `BeginFrame` sweep of `RenderSceneIndex.IndoorCellStatic`/`OutdoorStatic` (a borrow, not a recompute) | `WalkFrameDriver.GetCellStatics`; `RetailPViewRenderer` particle owner union; unregistered fallback (indoor: authored `ParentCellId`; outdoor: `GetOwnerCells`) counted by `WalkProductionWorldData.UnregisteredStaticRenderFallbackCount` |
+| **END STATE (chunk 5, 2026-09-03).** `WalkProductionWorldData.GetCellStatics`/`GetCellDynamics`/`GetOutdoorStatics`/`GetOutdoorDynamics` → `ShadowObjectRegistry.GetRetailPartEntriesInCell(cellId)` → distinct entity ids in entry order → `RenderSceneQuery.TryGetByLocalEntityId` (`WalkProductionWorldData.cs` `ResolveCellView`; `RenderSceneContracts.cs`/`ArchRenderScene.cs` new `TryGetByLocalEntityId`/`_byLocalEntityId`). Superseded, in order: `ResolveStaticRenderCells`/`ComputeStaticRenderCells` (chunk 2 deleted these) → `ResolveIndoorStaticRenderCells`/`ResolveOutdoorStaticRenderCells`/`ResolveDynamicRenderCells` + the five per-cell bucket dictionaries + the three per-frame scene sweeps (chunk 5 deletes ALL of these) | none (borrowed, per QUERIED cell, on demand — no per-frame sweep of the scene at all any more) | one cell's retail `RetailPartEntry` rows, filtered to the record's own `ProjectionClass` (static vs. dynamic) and excluding `IsBuildingShell` | every `Get*` call at a walk turn (lazy, cached per cell per frame in the SAME `_cellCache`/`_cellDynamicCache`/`_outdoorMaterialized`/`_outdoorDynamicsMaterialized` dictionaries chunk 2 introduced) | `WalkFrameDriver.GetCellStatics`/`GetCellDynamics`/`GetOutdoorStatics`/`GetOutdoorDynamics`; `RetailPViewRenderer` particle owner union (`GetCellStatics`, unchanged call); unregistered fallback is now "contributes to no cell" (no authored-parent or root-position substitute), counted by the renamed `WalkProductionWorldData.UnregisteredRenderMembershipCount` (once per DISTINCT entity per frame, not per cell visit) — AD-116 |
 | **Chunk 4 (2026-09-02).** `LiveEntityCollisionBuilder.Register` / `ShadowObjectRegistry.UpdatePosition` / `CommitSetPosition` (`LiveEntityCollisionBuilder.cs:149-280`, `ShadowObjectRegistry.cs`) | `ShadowShapeBuilder.FromSetup` (collision dispatch) + `FromSetupRenderParts` (chunk 1b's part array) → the same ONE Contract A flood as above at registration; movement (`UpdatePosition`/`CommitSetPosition`'s `Recalculate` action) forwards to the same registration entry points, so it inherits the fix. **RESOLVED (chunk 4):** `CommitSetPosition`'s `None`/`Preserve`/`Replace` actions (`RefreshPositionRows`/`ReplacePositionRows`) now publish the retail render product from the SAME exact collision cell list the move just used (`PublishRetailProductFromExactCells`) — the independent Contract A recompute chunk 1/3 ran on every move (`RecomputeRetailCellArrayIfPresent`) is deleted. Mirrors retail `SetPositionInternal`'s `add_shadows_to_cells(this, &arg2->cell_array)` (pc:283536-283537), which consumes the transition's own array for both products in one call; the `num_cells > 0` keep-when-empty gate (pc:283540) now covers both products identically | `_entityToCells` + `_cells`, and (when a part array is retained) `_retailCellArrays`/`_retailPartEntriesByCell`, both from the SAME exact cell list on every move | spawn and every accepted move/appearance change | physics broadphase; `WalkProductionWorldData` dynamic render lookup (now a direct `TryGetRetailCellArray` read, see below) |
 | **Chunk 4 (2026-09-02).** The staged `ShadowObjectRegistry.TryPrepareSetPosition`/`TryApplySetPosition` pipeline | `PreparedShadowOwnerState` carries `RetailPartArray`/`RetailCellIds`/`RetailRoute`/`RetailRows`; `TryCaptureOwnerState`/`InstallOwnerState` seed them so the staging registry's own `CommitSetPosition` call inherits chunk 4's one-array-two-products move path for free; `PrepareRetailPartEntryReplacements` diffs the staged retail rows the same way `PrepareCellReplacements` diffs collision rows; `TryApplySetPosition` additionally calls `RepublishAttachedChildren` on the LIVE registry after publishing, since the staging registry carries none of the live attach-chain state | `_retailPartEntriesByCell` publishes alongside `_cells` on `TryApplySetPosition`; every attached child of the moved root republishes too | every live entity moving through the transactional SetPosition publication tail (Runtime) | same as direct `CommitSetPosition`, now consistent with it |
 | **Chunk 4 (2026-09-02).** `ShadowObjectRegistry.AttachChild`/`DetachChild` (`ShadowObjectRegistry.cs`) — retail's `add_shadows_to_cells` child-inheritance recursion (Contract B) | `EquippedChildRenderController.TryRealize` calls `AttachChild(childEntityId, rootEntityId, childPartArray)` at the exact moment the attached projection's `WorldEntity` is registered against its accepted parent, using `ShadowShapeBuilder.FromSetupRenderParts` over the SAME `PhysicsDataCache` resolvers `LiveEntityCollisionBuilder` uses; `CommitProjectionRemoval` (the single withdrawal/unparent/teardown funnel) calls `DetachChild`. A nested attachment (child of a child) resolves to the ultimate root by walking the existing chain, bounded and cycle-safe | new `_childParent`/`_parentChildren`/`_childPartArrays` dictionaries (own `CollisionWorldState` fields, reset with everything else); PART ENTRIES only for the child — never a collision row, since acdream's attached projections own no independent collision shapes | attach/detach, and every time the root's array republishes (registration, move, staged apply, `ReplaceMultiPartPayload`) | `WalkProductionWorldData.ResolveDynamicRenderCells` (a plain `TryGetRetailCellArray` read on the CHILD's own id — no parent walk) |
-| **RESOLVED (chunk 4).** `WalkProductionWorldData.ResolveDynamicRenderCells` (`WalkProductionWorldData.cs`) | `ShadowObjectRegistry.TryGetRetailCellArray` directly, for every dynamic record including equipped children (their array is published at attach time by the registry, above); unregistered fallback is `GetOwnerCells`, counted by the SAME `UnregisteredStaticRenderFallbackCount` the static buckets use — the render-side 64-hop parent-chain walk and its `FindParentLocalId` plumbing into this class are deleted | whole-record buckets | every `BeginFrame` | `WalkFrameDriver.GetCellDynamics` |
+| **DELETED (chunk 5).** Was `WalkProductionWorldData.ResolveDynamicRenderCells` (a per-record `TryGetRetailCellArray` read). Dynamics now share the SAME `ResolveCellView` end-state row above as statics — no record-keyed lookup, no separate dynamic resolver, no separate fallback | — | — | — | superseded by the END STATE row above |
 | `LightManager.SelectForCell` (`LightManager.cs:594-650`) | flat `_all` list, sphere overlap | per-cell light subset | per cell drawn | lighting (S5 owns; retail selects from the current EnvCell + stab list) |
 | `DirectionalShadowCasterFrame` (`DirectionalShadowCasterFrame.cs:229-233`) | flat outdoor indices, no cell filter | caster list | per frame | shadow pass (S5) |
 | Topology: `EnvCellLandblockBuildBuilder.BuildVisibilityCell` vs `WalkCellFactory.FromParsed` vs `FlatEnvCellTopology` | same DAT / pak | three distinct portal graphs (`LoadedCell`, `WalkCell`, flat asset) | per landblock build | render, walk, `CellTransit` |
@@ -117,10 +117,11 @@ movement; particles own-cell only (still no production path reaches this
 registry — chunk 3's finding stands, deferred); the render-side parent-chain
 walk is deleted. See §7.
 
-**Chunk 5 — consumer cutover and deletion.** Remaining `WalkProductionWorldData`
-buckets become borrowed views; particle owner-cell union reads the same;
-duplicate dictionaries and fallbacks are deleted; architecture text updated.
-Lights and directional shadows stay as they are (S5).
+**Chunk 5 — consumer cutover and deletion (landed 2026-09-03).** Remaining
+`WalkProductionWorldData` buckets become borrowed views; particle owner-cell
+union reads the same; duplicate dictionaries and fallbacks are deleted;
+architecture text updated. Lights and directional shadows stay as they are
+(S5). See §8 for the evidence.
 
 Owner gate G2 after chunk 5 (plan §9 S2).
 
@@ -479,3 +480,245 @@ nesting, and cycle rejection). App suite (hermetic lanes): 6,761/6,761 (was
 parent-chain-walk test replaced by two direct-registry tests). Runtime suite:
 1,884/1,884 (unchanged — chunk 4 touched no Runtime source). Full solution
 Release build: 0 warnings, 0 errors.
+
+## 8. Chunk 5 evidence (2026-09-03)
+
+**A — borrowed per-cell views.** `WalkProductionWorldData.BeginFrame`'s three
+per-frame scene sweeps (indoor static, outdoor static, dynamic) and their
+scratch arrays (`_indoorSweepScratch`, `_dynamicSweepScratch`), the five
+per-cell bucket dictionaries (`_indoorByCell`, `_indoorDynamicsByCell`,
+`_outdoorByCell`, `_outdoorDynamicsByCell`), `BucketIndoorRecord`/
+`BucketOutdoorRecord`/`BucketDynamicRecord`, and
+`ResolveIndoorStaticRenderCells`/`ResolveOutdoorStaticRenderCells`/
+`ResolveDynamicRenderCells` are all deleted. `GetCellStatics`/
+`GetCellDynamics`/`GetOutdoorStatics`/`GetOutdoorDynamics` share one private
+resolver, `ResolveCellView(cellId, dynamic)`: read
+`ShadowObjectRegistry.GetRetailPartEntriesInCell(cellId)` (already in retail
+CELLARRAY-then-part-array insertion order), collapse ADJACENT entries with
+the same `EntityId` to their distinct owning entity ids (safe because
+`PublishRetailPartEntries` always removes-then-re-adds a whole entity's rows
+atomically — one entity's own run for a cell is never interleaved with
+another's), resolve each id to its `RenderProjectionRecord` via the new
+`RenderSceneQuery.TryGetByLocalEntityId`, filter to the record's own
+static-vs-dynamic `ProjectionClass` (`LiveDynamicRoot`/`EquippedChild` are
+dynamic — the SAME split `ArchRenderScene.IsDynamic` already used
+privately), and exclude `IsBuildingShell`. Indoor vs. outdoor needs no
+dispatch of its own: the CALLER already queries the right id space (an
+indoor `GetCellStatics(cellId)` call and an outdoor `GetOutdoorStatics(cellId)`
+call each pass a cell id from their own id space), and the registry has
+already published the entity into every crossed cell under its true id
+either way. The per-frame result caches (`_cellCache`,
+`_cellDynamicCache`, `_outdoorMaterialized`, `_outdoorDynamicsMaterialized`)
+and the arena (`_arena`/`AppendToArena`) are UNCHANGED — chunk 5 adds one new
+grow-on-demand scratch buffer, `_cellViewScratch` (starts at 64 records),
+that `ResolveCellView` fills before a single `AppendToArena` call per cell,
+matching the existing `_sweepScratch` growth shape. Building shells keep
+their own narrow survivor sweep (`_shellsByAnchor`, `GetBuildingShellStatics`)
+exactly as before — out of S2's scope (the landcell building channel).
+
+The scene-side half of this borrow is new: `RenderSceneQuery` gains
+`TryGetByLocalEntityId(uint localEntityId, out RenderProjectionRecord)`
+(`RenderSceneContracts.cs`'s `IRenderSceneQuerySource` interface + the query
+struct forwarder), implemented in `ArchRenderScene` by a new
+`Dictionary<uint, RenderProjectionId> _byLocalEntityId` maintained at the
+SAME `AddToIndices`/`RemoveFromIndices` insertion points as the existing
+per-cell (`_cellStatics`/`_cellDynamics`) and per-class indices — purely
+presentation-side derived state, cleared by `ClearIndices` alongside
+everything else, never a second membership source. The one other
+`IRenderSceneQuerySource` implementation in the tree, the
+`DirectionalShadowCasterFrameTests.QuerySource` test fake, gained a matching
+linear-scan implementation so the interface stays satisfiable outside
+production.
+
+**B — effect-object render-only registration.** `LiveEntityCollisionBuilder.
+Build` (Runtime) now computes `renderParts` (`ShadowShapeBuilder.
+FromSetupRenderParts`) BEFORE its early-return gate, and returns a non-null
+`LiveEntityCollisionRegistration` whenever EITHER `shapes` (collision) or
+`renderParts` is non-empty (or `retainEmptyPayload` is set) — previously an
+empty `shapes` list alone (a Setup with visual parts but no CylSphere/
+Sphere/physics-BSP part) returned `null` unconditionally, silently dropping
+`renderParts` too and never reaching the registry at all. The materializer
+call site (`DatLiveEntityProjectionMaterializer.cs:751-763`) needed NO
+change: it already calls `LiveEntityCollisionBuilder.Register(_shadows,
+collision)` whenever `Build` returns non-null, and `Register` already
+forwards `registration.RenderParts` as `RegisterMultiPart`'s `partArray:`
+argument.
+
+`ShadowObjectRegistry.RegisterMultiPart`'s `shapes.Count == 0` branch no
+longer unconditionally deregisters: when a non-empty `partArray` is also
+supplied, it calls the new private `RegisterRenderOnly`, which floods via
+`ComputeContractACellArray` with an EMPTY `collisionShapes` argument (so
+Contract A's cylsphere test is always false and the bbox route always wins —
+"route per Contract A with an empty collision dispatch"), publishes the
+resulting CELLARRAY/`RetailPartEntry` rows exactly like any other
+registration, and retains `_entityShapes[entityId] = []` (not absent) so
+`UpdatePosition`'s `IsMultiPart && _entityShapes.TryGetValue` dispatch and
+`ReplacePositionRows`'s per-shape loop both take the correct "multi-part,
+zero shapes" branch on a later move instead of falling back to the
+single-shape `Register` path or synthesizing a bogus zero-radius collision
+entry. `ReplaceMultiPartPayload`'s own "not yet registered" early-return
+guard gained the same `partArray`-aware condition, and `ReplacePositionRows`
+gained a `wroteCollisionEntries` guard so a render-only entity moving
+through the direct (non-staged) `CommitSetPosition` path never gets a ghost
+`_entityToCells` entry with zero backing `ShadowEntry` rows. NO collision row
+is EVER published for a render-only entity — `GetOwnerCells` stays empty
+across register/move/deregister — matching Contract B exactly (an object
+contributes to `shadow_object_list` only when it has a part TO shadow
+there).
+
+One adjacent gap was found and left OPEN, not fixed: `ShadowObjectRegistry.
+RefloodOwnerForLandblock` (the STATIC/offline `LandblockPhysicsContentBuilder`
+streaming-reflood path, `AcDream.Content`) calls `RegisterMultiPart`/
+`Register` without forwarding the entity's retained `partArray` at all —
+since `RegisterMultiPart`'s body always `DeregisterCore`s (which clears the
+retail array) before re-flooding, ANY reflooded entity with a retained retail
+part array silently loses its render product on reflood, and a genuinely
+render-only entity would be deregistered outright (its `shapes.Count == 0`
+with no forwarded `partArray` hits the `Deregister` branch). This predates
+chunk 5 (it exists since chunk 1b/3 threaded `partArray:` through every OTHER
+call site) and is out of chunk 5's live-entity-materializer scope — no
+production live-entity path reaches `RefloodOwnerForLandblock` (only the
+offline static content builder does) — but it is a real gap for
+landblock-edge STATICS reflooded near a streaming boundary and should be
+scoped as its own small follow-up.
+
+**C — the one remaining fallback.** Under the borrowed-view model the
+former TWO fallback directions collapse to ONE. "Scene has a record, registry
+never registered it at all" is not observable any more — `ResolveCellView`
+only ever iterates registry entries, so such an entity is simply never
+visited (zero code, matching "an object not yet in a cell is not drawn"
+exactly, no counter). "Registry HAS flooded the entity into a cell, but the
+scene's projected record isn't resolvable yet" (the presentation journal
+lagging the physics publisher within the same frame) is the one real,
+observable race: `ResolveCellView`'s `!_scene.TryGetByLocalEntityId(...)`
+branch counts the entity ONCE per frame (via a per-frame `HashSet<uint>
+_unregisteredEntitiesThisFrame`, so an entity crossing several cells or
+queried through both the static/dynamic getter pair is not double-counted)
+into the renamed `WalkProductionWorldData.UnregisteredRenderMembershipCount`,
+and contributes to NO cell — no authored-parent or root-position substitute
+survives. `BeginFrame` prints one `[walk-membership] unregistered=N
+tupleLandblock=0x…` line, gated on the existing walk-family flag
+`RenderingDiagnostics.ProbeFacilityStairsEnabled` (reused, no new env var),
+reporting the PRIOR frame's final count at the start of the next
+`BeginFrame` — the only point a "frame is done" signal exists in this
+class's lazy, on-demand `Get*` model. AD-116 files this deviation citing
+AD-49's residency-race reasoning (the register's OTHER residency-timing row;
+the ownership-map's original chunk-2 citation of "AD-40" was already stale
+against the current register — AD-40 there is the unrelated fsf transient-bit
+row — AD-49 is the one that actually argues residency-race safety).
+
+**D — `GetOwnerCells` / `TryGetRetailCellArray` App-layer consumer audit.**
+`grep -rn "\.GetOwnerCells(" src/AcDream.App/ src/AcDream.Runtime/
+src/AcDream.Content/` after chunk 5 finds exactly ONE call site:
+`WalkProductionWorldData.EmitFacilityShadowProbe` (unchanged this chunk) —
+a diagnostic probe, gated on `ProbeFacilityStairsEnabled`, that PRINTS the
+collision-owner cell set for the authored Facility/cathedral stair
+SourceIds and the local player for comparison; it never feeds admission or
+membership. `grep -rn "\.TryGetRetailCellArray(\|\.GetRetailPartEntriesInCell("
+src/AcDream.App/` finds every call site inside `WalkProductionWorldData.cs`
+itself (`ResolveCellView`, `StaticBucketContains`) — nothing else in App
+reconstructs or reads registry membership. `RetailPViewRenderer`'s particle
+owner union calls `GetCellStatics` (the borrowed view), unchanged.
+
+**Test evidence.** Core `ShadowObjectRegistryRetailCellArrayTests`: 27/27
+(was 22; +5 new fixtures covering item B's render-only registration,
+keep-when-empty, deregister, and move). App `LiveEntityCollisionBuilderTests`:
+13/13 (was 12; +1 covering `Build`/`Register` producing a render-only
+registration end to end against a real registry). App
+`WalkProductionWorldDataTests`: 11/11 (was 12 pre-chunk-5 — 8 bucket-primitive
+tests and 2 `ResolveDynamicRenderCells` tests deleted with their methods, 9
+new tests added against the real production path — a real bare
+`ShadowObjectRegistry` + real `ArchRenderScene`, never a hand-fed bucket
+dictionary — covering registry-driven resolution, the one remaining
+fallback + its per-entity-not-per-cell counting, static/dynamic split,
+building-shell exclusion, outdoor parity, per-frame caching, and
+`StaticBucketContains`). Net App suite delta: 0 (6,761/6,761 both before and
+after, since the file-level and materializer-level deltas cancel exactly).
+`Issue177StairDescentCameraFloodTests.FacilityStairAssembly_
+RegisterAcross015FTo015E` (Lane=InstalledDat) required only the
+`UnregisteredStaticRenderFallbackCount` → `UnregisteredRenderMembershipCount`
+rename — its own registry/scene wiring already matches the chunk-5 model
+byte-for-byte since it looks records up by `LocalEntityId`, not by any
+formulaic id.
+
+**Automated gate.** Full Release solution build: 0 warnings, 0 errors. Core
+`Lane!=Timing&Lane!=Linux`: 4,975/4,975 (4,970 + 5 new). App hermetic lanes:
+6,761/6,761 (unchanged net). App `Lane=InstalledDat`: 147 passed / 97 skipped
+/ 1 failed — the one failure,
+`TowerAscentReplayTests.TowerAscent_StaircaseStaysConeVisible_EveryStep`,
+is PRE-EXISTING and unrelated: the test file has no reference to
+`WalkProductionWorldData` or `ShadowObjectRegistry` at all, its last commit
+predates Campaign OVERHAUL entirely, and `docs/ISSUES.md`'s #119-residual
+entry already documents this exact pin as needing re-validation against the
+production resolver before it can be trusted ("its band came from the
+harness's AABB root model, not the production sweep") — an S3-scope
+viewcone/cone-cull concern, not S2 membership. Runtime
+`Lane!=Timing&Lane!=Linux`: 1,884/1,884 (unchanged — chunk 5 touched no
+Runtime test-visible behavior beyond `LiveEntityCollisionBuilder.Build`'s
+early-return condition, already covered from the App side).
+
+**Allocation note.** `ResolveCellView` performs no per-call heap allocation
+after warmup: `GetRetailPartEntriesInCell` returns an existing `List<T>`
+cast to `IReadOnlyList<T>` (no copy), the entity-id dedup loop is a plain
+`for` over that list with two `uint` locals, `_cellViewScratch` is a
+grow-on-demand array reused every call (doubles only when a cell's
+membership exceeds its current capacity), and `AppendToArena` copies into
+the existing per-frame arena (`_arena`), also grow-on-demand. The one
+per-frame allocation-shaped addition is `_unregisteredEntitiesThisFrame`
+(a `HashSet<uint>`, cleared not reallocated every `BeginFrame`, same
+grow-once-then-stable shape as every other per-frame dictionary/set in this
+class) — its `.Add(uint)` calls are non-boxing value-type operations.
+
+## 9. S2 closeout: the reflood gap, the G2 self-gate finding, and the review fix round (2026-09-03)
+
+**Reflood (lead, landing chunk 5).** `RefloodOwnerForLandblock` re-registered
+from `_entityShapes` only, so every owner reflooded by a landblock replacement
+commit (`PhysicsEngine.ApplyCommittedOwnerReplacement`) or by the Content
+builder's post-publication reflood lost its retail product — with chunk 5's
+consumer reading nothing else, it vanished. Fixed by forwarding the retained
+`_entityRetailPartArrays` entry exactly as `UpdatePosition` already did
+(retail: a reflood is `recalc_cross_cells` over the SAME `CPartArray`). Pins:
+`RefloodLandblock_KeepsTheRetailProductOfACollisionOwnerWithAPartArray`,
+`RefloodLandblock_KeepsARenderOnlyOwner` (both fail without the fix).
+
+**G2 self-gate finding (pixel diff, not eyes).** Frame `02-facility-stairs.png`
+differed from the chunk-4 run in 23% of pixels; the chunk-4/baseline frames
+show the wall panels beside the corridor lit by its purple lights (left-wall
+mean RGB 65,17,21 baseline / 78,20,25 chunk 4) while the chunk-5 frame shows
+plain grey stone (29,26,23) with the drudge still pink-lit. Not lighting: the
+panels are DAT statics with no collision geometry, and `PublishStaticEntity`
+registered a static only under `entityBspCount > 0` / `setupShapes.Count > 0`
+— they had only ever been drawn through the parent-cell fallback chunk 5
+deleted. `UnregisteredRenderMembershipCount` stayed 0 because it counts the
+registry→scene direction only. Retail floods every object regardless of
+collision (`CEnvCell::init_static_objects` 0x0052c350 → `add_obj_to_cell`;
+`add_shadows_to_cells` 0x00514ae0 adds the shadow row unconditionally and
+gates only `AddPartsShadow` on `part_array != 0`). Fix: both publishers
+register a non-colliding static render-only (`RegisterMultiPart` with empty
+shapes + the part array → `RegisterRenderOnly`). Pins:
+`CompletePublication_NonCollidingStaticRegistersRenderOnly` (App),
+`PublishStaticCollision_NonCollidingGfxObjStatic_RegistersRenderOnly`
+(Content).
+
+**Review fix round (arch lens + retail lens, both Opus, every finding
+lead-verified against the source before any edit).**
+
+| # | Finding (verified) | Fix | Pin |
+|---|---|---|---|
+| A1/R2 | `Suspend` removed collision rows only; a suspended remote kept render membership at its last cells | `Suspend` clears the retail rows + republishes children; part array/route retained; the un-suspending `.None` commit republishes from the retained cells | `Suspend_ClearsTheRetailProduct_AndTheUnsuspendingMoveRepublishesIt` |
+| A2 | `AttachChild`/`DetachChild` never advanced `_mutationRevision`, so a prepared SetPosition's wholesale cell-list install could drop an attached child's rows | both advance the revision | `AttachChild_AndDetachChild_AdvanceTheMutationRevision` |
+| A3 | a re-registration of an attached child (appearance update) flooded it independently, overriding the inherited root array | `PublishRetailCellArray` short-circuits for an attached child: refresh `_childPartArrays`, `PublishChildEntries` | `RegisterMultiPart_OfAnAttachedChild_KeepsInheritingTheRootsCells` |
+| A4/R4 | `RemoveLandblock` and the non-rooted `RetireOwnerFromLandblock` branch left every retail row behind (unbounded growth, stale membership); render-only statics were unreachable by the static-retirement loop | `RemoveRetailProductForPrefix` (rows for the prefix's cells, per-owner cell pruning, static/render-only owners end with the landblock); the retire branch prunes retail cells first and handles render-only owners | `RemoveLandblock_ClearsTheRetailProduct_IncludingRenderOnlyStatics`, `RetireOwnerFromLandblock_PrunesTheRetailRowsOfANonRootedOwner` |
+| R3 | `RefreshPositionRows` (`.None`/keep-when-empty) republished from collision cells only → a render-only owner could never move | terminal branch republishes a render-only owner at its destination seed cell (AD-117 item 1) | `CommitSetPosition_None_MovesARenderOnlyOwnerToItsDestinationCell` |
+| A9 | `ReplaceMultiPartPayload` with a non-null EMPTY part array left a cell array with no rows and a permanent no-op on later moves | `partArray is { Count: > 0 }` | `ReplaceMultiPartPayload_WithAnEmptyPartArray_KeepsThePriorRows` |
+| A7/A8 | `RemoveAll` closure per cell per move; LINQ `Where().ToArray()` in the staged capture | `RemoveOwnerPartRows` + `CollectOwnerRows`/`CollectOwnerPartRows` | existing suites |
+| A5 | EnvCell shell projections carry their CELL id as `LocalEntityId`; dungeon cell ids alias the `0x8…` scenery namespace in `_byLocalEntityId` | shells are not indexed | `TryGetByLocalEntityId_IgnoresEnvCellShellRecords` |
+| A6 | `IndexMembershipEquals` omitted `LocalEntityId`, so an in-place id rebind left the index stale | compares the id | `Update_ThatRebindsTheLocalEntityId_MovesTheIndex` |
+| A10 | `_cellStatics`/`_cellDynamics` + `GetCellCount`/`CopyCellTo`/`GetCellStaticCount`/`CopyCell*To` had zero production callers | deleted | `ArchRenderSceneTests` updated |
+| A11/A12, R5–R7 | live list handed out; probe-flag coupling; unloaded-neighbour rows; circumsphere cheap reject; particle branch | documented (AD-117 items 2–4; S5 tail) | — |
+
+Verified-correct list from both reviews (kept for S5): Contract A dispatch,
+`find_bbox_cell_list` shape, `AddPartsShadow` order/clip-plane rule,
+movement from the transition's array, keep-when-empty, child inheritance
+order, `Deregister` symmetry, cross-generation adoption seeding the part
+array, ordering determinism, zero-alloc `ResolveCellView`, layering.

src/AcDream.App/Rendering/Scene/Arch/ArchRenderScene.cs

@@ -31,10 +31,11 @@ internal sealed class ArchRenderScene : IRenderScene, IRenderSceneQuerySource
     private readonly HashSet<RenderProjectionId> _selectable = [];
     private readonly HashSet<RenderProjectionId> _lightCandidates = [];
     private readonly HashSet<RenderProjectionId> _dirty = [];
-    private readonly Dictionary<uint, HashSet<RenderProjectionId>>
-        _cellStatics = [];
-    private readonly Dictionary<uint, HashSet<RenderProjectionId>>
-        _cellDynamics = [];
+    // Campaign OVERHAUL S2 chunk 5: presentation-side lookup by the entity's
+    // stable LocalEntityId — see IRenderSceneQuerySource.TryGetByLocalEntityId.
+    // Maintained at the same register/update/unregister points as the cell
+    // indices above; never a membership source.
+    private readonly Dictionary<uint, RenderProjectionId> _byLocalEntityId = [];
     private ArchWorld _world;
     private RenderProjectionCounts _counts;
     private ulong _lastAppliedJournalSequence;
@@ -434,6 +435,23 @@ internal sealed class ArchRenderScene : IRenderScene, IRenderSceneQuerySource
         return false;
     }
 
+    bool IRenderSceneQuerySource.TryGetByLocalEntityId(
+        RenderSceneGeneration generation,
+        uint localEntityId,
+        out RenderProjectionRecord record)
+    {
+        EnsureQueryGeneration(generation);
+        if (_byLocalEntityId.TryGetValue(localEntityId, out RenderProjectionId id)
+            && _entries.TryGetValue(id, out SceneEntry entry))
+        {
+            record = ReadRecord(in entry);
+            return true;
+        }
+
+        record = default;
+        return false;
+    }
+
     int IRenderSceneQuerySource.CopyById(
         RenderSceneGeneration generation,
         ReadOnlySpan<RenderProjectionId> ids,
@@ -499,31 +517,6 @@ internal sealed class ArchRenderScene : IRenderScene, IRenderSceneQuerySource
         return CopyIdsTo(source, destination);
     }
 
-    int IRenderSceneQuerySource.GetCellCount(
-        RenderSceneGeneration generation,
-        uint fullCellId,
-        bool dynamic)
-    {
-        EnsureQueryGeneration(generation);
-        Dictionary<uint, HashSet<RenderProjectionId>> index =
-            dynamic ? _cellDynamics : _cellStatics;
-        return index.TryGetValue(fullCellId, out var ids) ? ids.Count : 0;
-    }
-
-    int IRenderSceneQuerySource.CopyCellTo(
-        RenderSceneGeneration generation,
-        uint fullCellId,
-        bool dynamic,
-        Span<RenderProjectionRecord> destination)
-    {
-        EnsureQueryGeneration(generation);
-        Dictionary<uint, HashSet<RenderProjectionId>> index =
-            dynamic ? _cellDynamics : _cellStatics;
-        return index.TryGetValue(fullCellId, out var ids)
-            ? CopyIdsTo(ids, destination)
-            : 0;
-    }
-
     private static ArchWorld CreateWorld() =>
         ArchWorld.Create(
             archetypeCapacity: InitialArchetypeCapacity,
@@ -809,21 +802,14 @@ internal sealed class ArchRenderScene : IRenderScene, IRenderSceneQuerySource
         if (staticProjection)
         {
             if (indoor)
-            {
                 _indoorCellStatics.Add(record.Id);
-                AddCell(_cellStatics, record.Residency.FullCellId, record.Id);
-            }
             else
-            {
                 _outdoorStatics.Add(record.Id);
-            }
         }
         else
         {
             _dynamics.Add(record.Id);
-            if (indoor)
-                AddCell(_cellDynamics, record.Residency.FullCellId, record.Id);
-            else
+            if (!indoor)
                 _outdoorDynamics.Add(record.Id);
             if ((record.Flags & RenderProjectionFlags.PortalStraddling) != 0)
                 _portalStraddlingDynamics.Add(record.Id);
@@ -837,6 +823,17 @@ internal sealed class ArchRenderScene : IRenderScene, IRenderSceneQuerySource
             _lightCandidates.Add(record.Id);
         if (record.DirtyMask != RenderDirtyMask.None)
             _dirty.Add(record.Id);
+        // An EnvCell shell projection carries its CELL id in the entity-id
+        // slot (StaticRenderProjectionJournal.ProjectEnvCellShell); cell ids
+        // with a 0x8_ high nibble alias the procedural-scenery entity
+        // namespace, so shells never enter this index (S2 review F5) — the
+        // walk reaches them through the leaf-renderer shell path, never by
+        // entity id. A shell is the one record built WITHOUT an entity
+        // payload (every static/dynamic entity record carries its MeshRefs
+        // from RenderProjectionRecordFactory); the projection class cannot
+        // tell them apart because interior statics share IndoorCellStatic.
+        if (record.Source.LocalEntityId != 0 && !IsEnvCellShell(in record))
+            _byLocalEntityId[record.Source.LocalEntityId] = record.Id;
         AdvanceIndexRevision();
         AdvanceDirectionalShadowTopologyRevision();
     }
@@ -852,12 +849,24 @@ internal sealed class ArchRenderScene : IRenderScene, IRenderSceneQuerySource
         _selectable.Remove(record.Id);
         _lightCandidates.Remove(record.Id);
         _dirty.Remove(record.Id);
-        RemoveCell(_cellStatics, record.Residency.FullCellId, record.Id);
-        RemoveCell(_cellDynamics, record.Residency.FullCellId, record.Id);
+        if (record.Source.LocalEntityId != 0
+            && _byLocalEntityId.TryGetValue(
+                record.Source.LocalEntityId,
+                out RenderProjectionId mapped)
+            && mapped == record.Id)
+        {
+            _byLocalEntityId.Remove(record.Source.LocalEntityId);
+        }
         AdvanceIndexRevision();
         AdvanceDirectionalShadowTopologyRevision();
     }
 
+    /// <summary>The record is an EnvCell shell (cell geometry), not an
+    /// entity: no entity payload was ever attached. See AddToIndices.</summary>
+    private static bool IsEnvCellShell(in RenderProjectionRecord record) =>
+        record.ProjectionClass == RenderProjectionClass.IndoorCellStatic
+        && record.EntityPayload.MeshRefs is null;
+
     private static bool IndexMembershipEquals(
         in RenderProjectionRecord left,
         in RenderProjectionRecord right)
@@ -870,6 +879,8 @@ internal sealed class ArchRenderScene : IRenderScene, IRenderSceneQuerySource
             | RenderProjectionFlags.SpatiallyResident;
 
         return left.ProjectionClass == right.ProjectionClass
+            // _byLocalEntityId is keyed by this field (S2 review F6).
+            && left.Source.LocalEntityId == right.Source.LocalEntityId
             && left.Source.ParentCellId == right.Source.ParentCellId
             && left.Residency.FullCellId == right.Residency.FullCellId
             && (left.Flags & indexedFlags) == (right.Flags & indexedFlags)
@@ -1141,33 +1152,6 @@ internal sealed class ArchRenderScene : IRenderScene, IRenderSceneQuerySource
         projectionClass is RenderProjectionClass.LiveDynamicRoot
             or RenderProjectionClass.EquippedChild;
 
-    private static void AddCell(
-        Dictionary<uint, HashSet<RenderProjectionId>> index,
-        uint fullCellId,
-        RenderProjectionId id)
-    {
-        if (fullCellId == 0)
-            return;
-        if (!index.TryGetValue(fullCellId, out HashSet<RenderProjectionId>? ids))
-        {
-            ids = [];
-            index.Add(fullCellId, ids);
-        }
-        ids.Add(id);
-    }
-
-    private static void RemoveCell(
-        Dictionary<uint, HashSet<RenderProjectionId>> index,
-        uint fullCellId,
-        RenderProjectionId id)
-    {
-        if (!index.TryGetValue(fullCellId, out HashSet<RenderProjectionId>? ids))
-            return;
-        ids.Remove(id);
-        if (ids.Count == 0)
-            index.Remove(fullCellId);
-    }
-
     private HashSet<RenderProjectionId> Index(RenderSceneIndex index) =>
         index switch
         {
@@ -1223,13 +1207,7 @@ internal sealed class ArchRenderScene : IRenderScene, IRenderSceneQuerySource
             + _selectable.EnsureCapacity(0)
             + _lightCandidates.EnsureCapacity(0)
             + _dirty.EnsureCapacity(0);
-        foreach (HashSet<RenderProjectionId> ids in _cellStatics.Values)
-            slots += ids.EnsureCapacity(0);
-        foreach (HashSet<RenderProjectionId> ids in _cellDynamics.Values)
-            slots += ids.EnsureCapacity(0);
-        long cellLookupSlots =
-            _cellStatics.EnsureCapacity(0)
-            + _cellDynamics.EnsureCapacity(0);
+        long cellLookupSlots = _byLocalEntityId.EnsureCapacity(0);
         return checked(slots * 24L + cellLookupSlots * 40L);
     }
 
@@ -1244,8 +1222,7 @@ internal sealed class ArchRenderScene : IRenderScene, IRenderSceneQuerySource
         _selectable.Clear();
         _lightCandidates.Clear();
         _dirty.Clear();
-        _cellStatics.Clear();
-        _cellDynamics.Clear();
+        _byLocalEntityId.Clear();
     }
 
     private void IncrementCount(RenderProjectionClass projectionClass)

src/AcDream.App/Rendering/Scene/RenderSceneContracts.cs

@@ -557,6 +557,22 @@ internal interface IRenderSceneQuerySource
         RenderProjectionId id,
         out RenderProjectionRecord record);
 
+    /// <summary>
+    /// Campaign OVERHAUL S2 chunk 5: a presentation-side lookup by the
+    /// entity's stable <see cref="RenderSourceMetadata.LocalEntityId"/> —
+    /// the SAME id <see cref="ShadowObjectRegistry"/>'s retail CELLARRAY and
+    /// per-cell <c>RetailPartEntry</c> rows are keyed by. This is derived
+    /// presentation state (maintained alongside the existing per-cell/
+    /// per-class indices at the same register/update/unregister points),
+    /// never a second membership source: cell membership still comes from
+    /// the registry alone, this only resolves an entity id back to its
+    /// current projected record.
+    /// </summary>
+    bool TryGetByLocalEntityId(
+        RenderSceneGeneration generation,
+        uint localEntityId,
+        out RenderProjectionRecord record);
+
     int CopyById(
         RenderSceneGeneration generation,
         ReadOnlySpan<RenderProjectionId> ids,
@@ -572,16 +588,10 @@ internal interface IRenderSceneQuerySource
         RenderSceneIndex index,
         Span<RenderProjectionRecord> destination);
 
-    int GetCellCount(
-        RenderSceneGeneration generation,
-        uint fullCellId,
-        bool dynamic);
-
-    int CopyCellTo(
-        RenderSceneGeneration generation,
-        uint fullCellId,
-        bool dynamic,
-        Span<RenderProjectionRecord> destination);
+    // Campaign OVERHAUL S2 review fix (arch F10): the per-cell scene indices
+    // (GetCellCount/CopyCellTo, keyed by the single authored FullCellId) are
+    // deleted — the registry's retail CELLARRAY is the ONLY render-membership
+    // source (ShadowObjectRegistry.GetRetailPartEntriesInCell).
 }
 
 internal readonly struct RenderSceneQuery
@@ -626,6 +636,11 @@ internal readonly struct RenderSceneQuery
         out RenderProjectionRecord record) =>
         Source.TryGet(Generation, id, out record);
 
+    public bool TryGetByLocalEntityId(
+        uint localEntityId,
+        out RenderProjectionRecord record) =>
+        Source.TryGetByLocalEntityId(Generation, localEntityId, out record);
+
     public int CopyById(
         ReadOnlySpan<RenderProjectionId> ids,
         Span<RenderProjectionRecord> destination) =>
@@ -644,30 +659,6 @@ internal readonly struct RenderSceneQuery
         Span<RenderProjectionRecord> destination) =>
         Source.CopyIndexTo(Generation, index, destination);
 
-    public int GetCellStaticCount(uint fullCellId) =>
-        Source.GetCellCount(Generation, fullCellId, dynamic: false);
-
-    public int CopyCellStaticsTo(
-        uint fullCellId,
-        Span<RenderProjectionRecord> destination) =>
-        Source.CopyCellTo(
-            Generation,
-            fullCellId,
-            dynamic: false,
-            destination);
-
-    public int GetCellDynamicCount(uint fullCellId) =>
-        Source.GetCellCount(Generation, fullCellId, dynamic: true);
-
-    public int CopyCellDynamicsTo(
-        uint fullCellId,
-        Span<RenderProjectionRecord> destination) =>
-        Source.CopyCellTo(
-            Generation,
-            fullCellId,
-            dynamic: true,
-            destination);
-
     private IRenderSceneQuerySource Source =>
         _source
         ?? throw new InvalidOperationException("The render-scene query is uninitialized.");

src/AcDream.App/Rendering/Walk/WalkProductionWorldData.cs

@@ -9,70 +9,70 @@ namespace AcDream.App.Rendering.Walk;
 /// <summary>
 /// Campaign FW3.2b-2: the production <see cref="IWalkFrameWorldData"/> over
 /// the retained scene (<see cref="RenderSceneQuery"/>) and the FW3.1
-/// <see cref="WalkBuildingRegistry"/>. Rebuilt facts per frame via
-/// <see cref="BeginFrame"/>:
+/// <see cref="WalkBuildingRegistry"/>.
 ///
-/// <list type="bullet">
-/// <item>Cell statics — ONE <see cref="RenderSceneQuery.CopyIndexTo"/> sweep
-/// over authored indoor statics, bucketed into every cell of
-/// <see cref="ShadowObjectRegistry.TryGetRetailCellArray"/>'s retail
-/// CELLARRAY. Campaign OVERHAUL S2 chunk 2: membership is BORROWED from that
-/// registry — the sole owner of retail's <c>calc_cross_cells_static</c>
-/// (0x00515160) → <c>CPartArray::AddPartsShadow</c> (0x00517e40) transaction
-/// — never rebuilt in this class. A registered entity's array deliberately
-/// includes non-colliding decorations and is distinct from the physics
-/// shadow-object index (<see cref="ShadowObjectRegistry.GetOwnerCells"/>).
-/// An entity the registry has not registered yet (the streaming window
-/// where the static-projection journal published the record before the
-/// physics publisher registered the entity — two independent incremental
-/// state machines) falls back to its authored
-/// <see cref="RenderSourceMetadata.ParentCellId"/> alone and is counted in
-/// <see cref="UnregisteredStaticRenderFallbackCount"/>. Per-cell PART
-/// entries (<see cref="ShadowObjectRegistry.GetRetailPartEntriesInCell"/>)
-/// are not consumed here — buckets stay whole-record per cell, which equals
-/// CELLARRAY membership; per-part draw admission is Campaign OVERHAUL S3.</item>
-/// <item>Live dynamics — ONE global dynamic-index sweep, bucketed into every
-/// cell in the object's retained physics <c>CELLARRAY</c>. Retail feeds that
-/// exact array to <c>CPhysicsObj::add_shadows_to_cells</c>, which calls
-/// <c>CPartArray::AddPartsShadow</c> for every member cell. A creature crossing
-/// a stair portal must therefore remain drawable from both the feet cell and
-/// the head cell; indexing only by its authored parent makes individual body
-/// parts disappear at the portal edge.</item>
-/// <item>Outdoor statics — ONE <see cref="RenderSceneQuery.CopyIndexTo"/>
-/// sweep bucketed the same way as cell statics — the registry's retail
-/// CELLARRAY first, falling back to
-/// <see cref="ShadowObjectRegistry.GetOwnerCells"/> (counted the same way)
-/// when unregistered — EXCLUDING building shells (they draw at their
-/// building's own shell turn, retail <c>CPhysicsPart::Draw(parts, 0)</c>
-/// @0x0059f331, not at the cell's <c>DrawObjCell</c> turn).</item>
-/// <item>Building shells — the same sweep's <c>IsBuildingShell</c> records
-/// bucketed by <c>Source.BuildingShellAnchorCellId</c> for portal-bearing
-/// buildings. Portal-less buildings have no interior anchor; retail still
-/// draws them at their landscape position-cell turn, so those records use
-/// <c>Source.EffectCellId</c>, matching <see cref="WalkBuilding.PositionCellId"/>.</item>
-/// </list>
+/// <para>
+/// Campaign OVERHAUL S2 chunk 5: cell membership is a BORROWED VIEW over
+/// <see cref="ShadowObjectRegistry"/>'s retail per-cell part-entry product
+/// (<see cref="ShadowObjectRegistry.GetRetailPartEntriesInCell"/> — retail's
+/// <c>CPartArray::AddPartsShadow</c> 0x00517e40 output, keyed by the SAME
+/// CELLARRAY <see cref="ShadowObjectRegistry.TryGetRetailCellArray"/>
+/// answers). This class no longer sweeps the scene's static/dynamic indices
+/// to REBUILD membership: for a queried cell id, <see cref="ResolveCellView"/>
+/// walks the registry's per-cell entries (already in retail
+/// CELLARRAY-then-part-array insertion order), collapses them to their
+/// distinct owning entity ids in that same order, and resolves each id back
+/// to its current <see cref="RenderProjectionRecord"/> through
+/// <see cref="RenderSceneQuery.TryGetByLocalEntityId"/> — a presentation-side
+/// lookup by the SAME <see cref="RenderSourceMetadata.LocalEntityId"/> the
+/// registry is keyed by (chunk 5's App-side addition to
+/// <c>ArchRenderScene</c>). Statics vs. dynamics are the same
+/// <c>ProjectionClass</c> split <c>ArchRenderScene</c> itself uses (a live
+/// dynamic root or an equipped child is "dynamic"; every other class is
+/// "static"), and building shells are excluded — they draw at their own
+/// building's shell turn (retail <c>CPhysicsPart::Draw(parts, 0)</c>
+/// @0x0059f331), never at the cell's ordinary <c>DrawObjCell</c> turn.
+/// </para>
 ///
-/// The tuple landblock id handed to the classifier is the frame's player
-/// landblock, matching the production walk's retained-scene query convention.
+/// <para>
+/// An entity the registry HAS flooded into this cell but whose projected
+/// record the presentation journal has not applied yet this frame (the
+/// transient race between <c>LiveEntityRuntime</c>'s projection journal and
+/// <c>ShadowObjectRegistry</c>'s physics-side registration, both driven off
+/// the same Create/appearance edge but landing through independent
+/// incremental pipelines) contributes to NO cell — retail draws nothing for
+/// an object not yet in a cell; there is no second, conservative fallback.
+/// Every DISTINCT entity id this happens for in one frame is counted once in
+/// <see cref="UnregisteredRenderMembershipCount"/>, regardless of how many
+/// cells its CELLARRAY touches or how many <c>Get*</c> calls observe it.
+/// </para>
 ///
-/// <para>Campaign FW3.4a: <see cref="GetCellStatics"/>, <see cref="GetOutdoorStatics"/>,
-/// and <see cref="GetBuildingShellStatics"/> used to materialize their result
-/// with <c>_cellScratch[..count]</c> / <c>[.. bucket]</c> — a FRESH
-/// <c>RenderProjectionRecord[]</c> allocation per distinct cell/anchor per
-/// frame. At a town-density frame (dozens of cells) that was the single
-/// largest contributor to the FW3.4 perf checkpoint's 14× frame-allocation
-/// regression (1.9 MB/frame p50). <see cref="_arena"/> replaces it: a
-/// grow-only buffer, reset to length 0 once per frame in
-/// <see cref="BeginFrame"/>, that every materialization call
-/// <see cref="AppendToArena"/>s its records into instead of snapshotting a
-/// new array — after the arena reaches its steady-state size (a few frames
-/// of warmup, same shape as <see cref="_sweepScratch"/>/<see cref="_cellScratch"/>'s
-/// existing grow-on-demand pattern), zero further heap allocation occurs
-/// here. Every <see cref="WalkFrameStaticRecords.Records"/> segment is
+/// <para>Building shells are the ONE exception left to a per-frame sweep:
+/// retail's shell/portal machinery is out of S2's scope (the landcell
+/// building channel), so <see cref="GetBuildingShellStatics"/> still reads a
+/// small per-frame bucket (<c>_shellsByAnchor</c>) filled by a single narrow
+/// <see cref="RenderSceneIndex.OutdoorStatic"/> sweep in
+/// <see cref="BeginFrame"/> that keeps only <c>IsBuildingShell</c> records —
+/// it never resolves ordinary static/dynamic membership.</para>
+///
+/// <para>Campaign FW3.4a: <see cref="GetCellStatics"/>, <see cref="GetCellDynamics"/>,
+/// <see cref="GetOutdoorStatics"/>, <see cref="GetOutdoorDynamics"/>, and
+/// <see cref="GetBuildingShellStatics"/> materialize their result into
+/// <see cref="_arena"/> — a grow-only buffer reset to length 0 once per frame
+/// in <see cref="BeginFrame"/> — rather than a fresh <c>RenderProjectionRecord[]</c>
+/// allocation per distinct cell/anchor per frame (the single largest
+/// contributor to the FW3.4 perf checkpoint's 14× frame-allocation
+/// regression, 1.9 MB/frame p50, before the arena existed).
+/// <see cref="_cellViewScratch"/> is the matching grow-on-demand scratch
+/// buffer <see cref="ResolveCellView"/> collects one cell's filtered records
+/// into before a single <see cref="AppendToArena"/> call — the same
+/// steady-state-zero-allocation shape <see cref="_sweepScratch"/> already
+/// has. Every <see cref="WalkFrameStaticRecords.Records"/> segment is
 /// STRICTLY per-frame scratch — nothing holds one across a frame boundary
-/// (the driver/populator consume it immediately, matching
-/// <see cref="_sweepScratch"/>'s existing lifetime contract) — so reusing the
-/// same backing array's memory next frame is safe.</para>
+/// (the driver/populator consume it immediately) — so reusing the same
+/// backing array's memory next frame is safe. Per-cell RESULTS
+/// (<see cref="_cellCache"/> etc.) are cleared and re-materialized once per
+/// frame on first ask, same as before chunk 5.</para>
 /// </summary>
 internal sealed class WalkProductionWorldData : IWalkFrameWorldData
 {
@@ -80,24 +80,32 @@ internal sealed class WalkProductionWorldData : IWalkFrameWorldData
     private readonly ShadowObjectRegistry _shadows;
     private RenderSceneQuery _scene;
     private uint _tupleLandblockId;
-    private int _renderCenterLbX;
-    private int _renderCenterLbY;
 
     private readonly Dictionary<uint, WalkFrameStaticRecords> _cellCache = new();
     private readonly Dictionary<uint, WalkFrameStaticRecords> _cellDynamicCache = new();
     private readonly Dictionary<string, string> _facilityShadowProbeSignatures = new();
-    private readonly Dictionary<uint, List<RenderProjectionRecord>> _indoorByCell = new();
-    private readonly Dictionary<uint, List<RenderProjectionRecord>> _indoorDynamicsByCell = new();
-    private readonly Dictionary<uint, List<RenderProjectionRecord>> _outdoorByCell = new();
-    private readonly Dictionary<uint, List<RenderProjectionRecord>> _outdoorDynamicsByCell = new();
     private readonly Dictionary<uint, List<RenderProjectionRecord>> _shellsByAnchor = new();
     private readonly Dictionary<uint, WalkFrameStaticRecords> _outdoorMaterialized = new();
     private readonly Dictionary<uint, WalkFrameStaticRecords> _outdoorDynamicsMaterialized = new();
     private readonly Dictionary<uint, WalkFrameStaticRecords> _shellMaterialized = new();
-    private readonly Func<uint, (bool Found, IReadOnlyList<uint> Cells)> _tryGetRetailCellArray;
-    private RenderProjectionRecord[] _indoorSweepScratch = new RenderProjectionRecord[256];
+
+    // Campaign OVERHAUL S2 chunk 5: every distinct entity id counted into
+    // UnregisteredRenderMembershipCount this frame, so the SAME entity
+    // touching several cells (or being asked for through both the static and
+    // dynamic Get* pair) is counted once — not once per cell visit. Cleared
+    // in BeginFrame alongside the counter itself.
+    private readonly HashSet<uint> _unregisteredEntitiesThisFrame = new();
+
+    // The one surviving per-frame sweep: building shells only (see this
+    // type's own doc comment). Statics/dynamics no longer sweep the scene at
+    // all — membership is a borrowed, on-demand view over the registry.
     private RenderProjectionRecord[] _sweepScratch = new RenderProjectionRecord[1024];
-    private RenderProjectionRecord[] _dynamicSweepScratch = new RenderProjectionRecord[256];
+
+    // Campaign OVERHAUL S2 chunk 5: ResolveCellView's grow-on-demand scratch
+    // buffer — collects one cell's filtered records before a single
+    // AppendToArena call. Starts small: a cell's real membership is usually
+    // a handful of parts, not the hundreds an old full-scene sweep held.
+    private RenderProjectionRecord[] _cellViewScratch = new RenderProjectionRecord[64];
 
     // Campaign FW3.4a: the per-frame, grow-only materialization arena — see
     // this type's own doc comment.
@@ -110,455 +118,135 @@ internal sealed class WalkProductionWorldData : IWalkFrameWorldData
     {
         _buildings = buildings ?? throw new ArgumentNullException(nameof(buildings));
         _shadows = shadows ?? throw new ArgumentNullException(nameof(shadows));
-        _tryGetRetailCellArray = TryGetRetailCellArrayForEntity;
-    }
-
-    private (bool Found, IReadOnlyList<uint> Cells) TryGetRetailCellArrayForEntity(uint entityId)
-    {
-        bool found = _shadows.TryGetRetailCellArray(entityId, out IReadOnlyList<uint> cells);
-        return (found, cells);
     }
 
     /// <summary>
-    /// Campaign OVERHAUL S2 chunk 2: how many indoor/outdoor static records
-    /// this frame fell back to a conservative single-cell membership
-    /// (indoor: the authored <see cref="RenderSourceMetadata.ParentCellId"/>;
-    /// outdoor: today's collision-flood
-    /// <see cref="ShadowObjectRegistry.GetOwnerCells"/> answer) because
-    /// <see cref="ShadowObjectRegistry.TryGetRetailCellArray"/> had no retail
-    /// CELLARRAY registered yet for the entity. Retail has no such gap —
-    /// <c>CEnvCell::init_static_objects</c> installs the CELLARRAY before a
-    /// static is ever drawable — so a nonzero count here reflects two
-    /// independent incremental state machines (the static-projection journal
-    /// versus the physics publisher) racing during streaming, not
-    /// steady-state behavior; see AD-40's residency reasoning in
-    /// <see cref="CellTransit.BuildShadowCellSetFromParts"/>. Reset to zero
-    /// at the start of every <see cref="BeginFrame"/>. Campaign OVERHAUL S2
-    /// chunk 5 decides this adaptation's fate against the connected-route
-    /// count.
+    /// Campaign OVERHAUL S2 chunk 5: how many DISTINCT entities this frame
+    /// were present in the registry's retail CELLARRAY (so
+    /// <see cref="ShadowObjectRegistry.GetRetailPartEntriesInCell"/> named
+    /// them) but had no resolvable <see cref="RenderProjectionRecord"/> yet
+    /// through <see cref="RenderSceneQuery.TryGetByLocalEntityId"/> — the
+    /// transient streaming window where the physics publisher's registration
+    /// outran the presentation journal's applied projection for the same
+    /// Create/appearance edge. Retail has no such gap
+    /// (<c>CEnvCell::init_static_objects</c> installs the CELLARRAY before a
+    /// static is ever drawable) so a nonzero count here reflects two
+    /// independent incremental state machines racing during streaming, not
+    /// steady-state behavior; filed as AD-116, citing the same residency-race
+    /// reasoning AD-49 already accepts for
+    /// <see cref="CellTransit.BuildShadowCellSetFromParts"/>'s own outdoor
+    /// seed. Such an entity
+    /// contributes to NO cell this frame — there is no second, conservative
+    /// fallback (chunk 5 removed the authored-parent-cell and
+    /// root-position-cell fallbacks chunk 2/4 carried). Reset to zero at the
+    /// start of every <see cref="BeginFrame"/>, after that PRIOR frame's
+    /// value has already been reported by the diagnostic line below.
     /// </summary>
-    public int UnregisteredStaticRenderFallbackCount { get; private set; }
+    public int UnregisteredRenderMembershipCount { get; private set; }
 
-    /// <summary>Rebuilds the frame's outdoor/shell buckets and clears the
-    /// per-cell cache. Call once per frame before the driver runs.
+    /// <summary>Rebuilds the frame's building-shell bucket and clears the
+    /// per-cell caches. Call once per frame before the driver runs.
     /// <paramref name="renderCenterLbX"/>/<paramref name="renderCenterLbY"/>
-    /// are the streaming recenter origin: record positions are
-    /// RENDER-ORIGIN-RELATIVE (each landblock's entities carry
-    /// <c>(lbX − CenterX)·192</c> offsets), so mapping a position back to
-    /// its TRUE landblock byte needs the center added back — the first
-    /// connected gate of the FW3.2b-2 cutover shipped without this and most
-    /// outdoor scenery landed in garbage buckets no walk turn ever reads.</summary>
+    /// were the streaming recenter origin the deleted position-based
+    /// fallbacks used to convert a render-origin-relative position back to
+    /// its true landblock byte (<c>LandscapeCellId</c>). Campaign OVERHAUL
+    /// S2 chunk 5 deleted every position-based fallback — the registry's
+    /// CELLARRAY is already expressed in exact cell ids — so these two
+    /// parameters are accepted (unchanged call-site signature) but no
+    /// longer stored or read.</summary>
     internal void BeginFrame(
         RenderSceneQuery scene,
         uint tupleLandblockId,
         int renderCenterLbX,
         int renderCenterLbY)
     {
+        // Campaign OVERHAUL S2 chunk 5: report the PRIOR frame's count
+        // before resetting it — the count is only final once that frame's
+        // walk (a sequence of on-demand Get* calls this class has no other
+        // "frame is done" hook for) has finished, so this is necessarily a
+        // one-frame-delayed report, matching every other per-second/per-
+        // change probe in this file family (print-only; never influences
+        // admission).
+        if (UnregisteredRenderMembershipCount > 0
+            && AcDream.Core.Rendering.RenderingDiagnostics.ProbeFacilityStairsEnabled)
+        {
+            Console.WriteLine(
+                $"[walk-membership] unregistered={UnregisteredRenderMembershipCount} "
+                + $"tupleLandblock=0x{_tupleLandblockId:X8}");
+        }
+
         _scene = scene;
         _tupleLandblockId = tupleLandblockId;
-        _renderCenterLbX = renderCenterLbX;
-        _renderCenterLbY = renderCenterLbY;
         _cellCache.Clear();
         _cellDynamicCache.Clear();
         _outdoorMaterialized.Clear();
         _outdoorDynamicsMaterialized.Clear();
         _shellMaterialized.Clear();
         _arenaLength = 0;
-        UnregisteredStaticRenderFallbackCount = 0;
-        foreach (List<RenderProjectionRecord> bucket in _indoorByCell.Values)
-            bucket.Clear();
-        foreach (List<RenderProjectionRecord> bucket in _indoorDynamicsByCell.Values)
-            bucket.Clear();
-        foreach (List<RenderProjectionRecord> bucket in _outdoorByCell.Values)
-            bucket.Clear();
-        foreach (List<RenderProjectionRecord> bucket in _outdoorDynamicsByCell.Values)
-            bucket.Clear();
+        UnregisteredRenderMembershipCount = 0;
+        _unregisteredEntitiesThisFrame.Clear();
         foreach (List<RenderProjectionRecord> bucket in _shellsByAnchor.Values)
             bucket.Clear();
 
-        // Retail CEnvCell::init_static_objects does not leave an object solely
-        // in its authored parent cell. add_obj_to_cell ->
-        // calc_cross_cells_static -> CPartArray::AddPartsShadow registers all
-        // visual parts in every crossed cell, including parts with no physics
-        // BSP. Campaign OVERHAUL S2 chunk 2: that membership is borrowed
-        // whole from ShadowObjectRegistry's retained retail CELLARRAY — never
-        // recomputed here.
-        int required = _scene.IndexCounts.For(RenderSceneIndex.IndoorCellStatic);
-        if (required > _indoorSweepScratch.Length)
-        {
-            _indoorSweepScratch = new RenderProjectionRecord[
-                Math.Max(required, _indoorSweepScratch.Length * 2)];
-        }
-        int count = _scene.CopyIndexTo(
-            RenderSceneIndex.IndoorCellStatic,
-            _indoorSweepScratch);
-        for (int i = 0; i < count; i++)
-        {
-            ref readonly RenderProjectionRecord record = ref _indoorSweepScratch[i];
-            IReadOnlyList<uint> renderCells = ResolveIndoorStaticRenderCells(
-                in record, _tryGetRetailCellArray, out bool usedFallback);
-            if (usedFallback)
-                UnregisteredStaticRenderFallbackCount++;
-            BucketIndoorRecord(
-                in record,
-                renderCells,
-                _indoorByCell,
-                _outdoorByCell);
-        }
-
-        // CopyIndexTo THROWS on an undersized destination (ArchRenderScene
-        // validates up front — the first connected gate run of the FW3.2b-2
-        // cutover crashed on exactly this at Aerlinthe's 5,040 outdoor
-        // statics), so presize from the query's own index counts.
-        required = _scene.IndexCounts.For(RenderSceneIndex.OutdoorStatic);
+        // Building shells are the landcell BUILDING channel (out of S2):
+        // retail draws a shell at its own DrawBuilding turn, never through
+        // the cell's ordinary shadow_part_list walk (Contract C), so this
+        // is the one sweep that survives chunk 5 — it exists ONLY to bucket
+        // IsBuildingShell records by their authored anchor, never to
+        // resolve ordinary static/dynamic cell membership.
+        int required = _scene.IndexCounts.For(RenderSceneIndex.OutdoorStatic);
         if (required > _sweepScratch.Length)
         {
             _sweepScratch = new RenderProjectionRecord[
                 Math.Max(required, _sweepScratch.Length * 2)];
         }
-        count = _scene.CopyIndexTo(RenderSceneIndex.OutdoorStatic, _sweepScratch);
+        int count = _scene.CopyIndexTo(RenderSceneIndex.OutdoorStatic, _sweepScratch);
         for (int i = 0; i < count; i++)
         {
             ref readonly RenderProjectionRecord record = ref _sweepScratch[i];
-            if (record.EntityPayload.IsBuildingShell)
-            {
-                uint anchor = BuildingShellBucketCellId(in record);
-                if (!_shellsByAnchor.TryGetValue(anchor, out List<RenderProjectionRecord>? shells))
-                    _shellsByAnchor[anchor] = shells = new List<RenderProjectionRecord>();
-                shells.Add(record);
+            if (!record.EntityPayload.IsBuildingShell)
                 continue;
-            }
-            IReadOnlyList<uint> renderCells = ResolveOutdoorStaticRenderCells(
-                in record, _tryGetRetailCellArray, _shadows.GetOwnerCells, out bool usedFallback);
-            if (usedFallback)
-                UnregisteredStaticRenderFallbackCount++;
-            BucketOutdoorRecord(
-                in record,
-                renderCells,
-                _outdoorByCell,
-                _renderCenterLbX,
-                _renderCenterLbY);
-        }
-
-        // Retail CPhysicsObj::add_shadows_to_cells installs every PartArray in
-        // every cell from calc_cross_cells' retained CELLARRAY. The scene's
-        // parent-cell dictionary cannot represent that membership, so consume
-        // the global dynamic index once and rebuild both indoor and outdoor
-        // render buckets from ShadowObjectRegistry's exact retained array.
-        required = _scene.IndexCounts.For(RenderSceneIndex.Dynamic);
-        if (required > _dynamicSweepScratch.Length)
-        {
-            _dynamicSweepScratch = new RenderProjectionRecord[
-                Math.Max(required, _dynamicSweepScratch.Length * 2)];
-        }
-        count = _scene.CopyIndexTo(
-            RenderSceneIndex.Dynamic,
-            _dynamicSweepScratch);
-        for (int i = 0; i < count; i++)
-        {
-            ref readonly RenderProjectionRecord record = ref _dynamicSweepScratch[i];
-            IReadOnlyList<uint> renderCells = ResolveDynamicRenderCells(
-                in record,
-                _tryGetRetailCellArray,
-                _shadows.GetOwnerCells,
-                out bool usedFallback);
-            if (usedFallback)
-                UnregisteredStaticRenderFallbackCount++;
-            BucketDynamicRecord(
-                in record,
-                renderCells,
-                _indoorDynamicsByCell,
-                _outdoorDynamicsByCell,
-                _renderCenterLbX,
-                _renderCenterLbY);
+            uint anchor = BuildingShellBucketCellId(in record);
+            if (!_shellsByAnchor.TryGetValue(anchor, out List<RenderProjectionRecord>? shells))
+                _shellsByAnchor[anchor] = shells = new List<RenderProjectionRecord>();
+            shells.Add(record);
         }
     }
 
-    /// <summary>
-    /// Campaign OVERHAUL S2 chunk 4: one dynamic record's render-cell
-    /// membership, borrowed from <see cref="ShadowObjectRegistry.TryGetRetailCellArray"/>
-    /// — the SAME direct read <see cref="ResolveOutdoorStaticRenderCells"/>
-    /// uses. An equipped child's retail array is now published by
-    /// <see cref="ShadowObjectRegistry.AttachChild"/> at the registry (retail
-    /// Contract B's <c>add_shadows_to_cells</c> child-inheritance recursion),
-    /// so this no longer needs its own render-side parent-chain walk — the
-    /// registry already resolved a nested attachment to its ultimate root.
-    /// When the registry has no retail array yet for this entity (the same
-    /// streaming-window race <see cref="ResolveIndoorStaticRenderCells"/>
-    /// documents), the fallback is today's collision-flood
-    /// <see cref="ShadowObjectRegistry.GetOwnerCells"/> answer, counted the
-    /// same way as the static fallbacks via <paramref name="usedFallback"/>.
-    /// </summary>
-    internal static IReadOnlyList<uint> ResolveDynamicRenderCells(
-        in RenderProjectionRecord record,
-        Func<uint, (bool Found, IReadOnlyList<uint> Cells)> tryGetRetailCellArray,
-        Func<uint, IReadOnlyList<uint>> getOwnerCells,
-        out bool usedFallback)
+    /// <summary>Facility Hub / cathedral discriminator: does the given cell's
+    /// borrowed retail render membership contain a record with this exact
+    /// authored SourceId? Reimplemented directly over the registry's
+    /// per-cell entries (chunk 5) rather than reading a swept bucket
+    /// dictionary — <see cref="RetailPViewRenderer"/>'s
+    /// <c>ProbeFacilityStairsEnabled</c> block is the only caller.</summary>
+    internal bool StaticBucketContains(uint cellId, uint sourceId)
     {
-        ArgumentNullException.ThrowIfNull(tryGetRetailCellArray);
-        ArgumentNullException.ThrowIfNull(getOwnerCells);
-
-        (bool found, IReadOnlyList<uint> cells) =
-            tryGetRetailCellArray(record.Source.LocalEntityId);
-        if (found)
+        IReadOnlyList<RetailPartEntry> entries =
+            _shadows.GetRetailPartEntriesInCell(cellId);
+        uint previousEntityId = 0;
+        bool havePrevious = false;
+        for (int i = 0; i < entries.Count; i++)
         {
-            usedFallback = false;
-            return cells;
-        }
-
-        usedFallback = true;
-        return getOwnerCells(record.Source.LocalEntityId);
-    }
-
-    /// <summary>
-    /// Campaign OVERHAUL S2 chunk 2: one authored indoor static's render-cell
-    /// membership, borrowed from <see cref="ShadowObjectRegistry.TryGetRetailCellArray"/>
-    /// — retail's <c>calc_cross_cells_static</c> (0x00515160) →
-    /// <c>CPartArray::AddPartsShadow</c> (0x00517e40) CELLARRAY. When the
-    /// registry has no retail array yet for this entity (the streaming window
-    /// where the static-projection journal published the record before the
-    /// physics publisher registered the entity — two independent incremental
-    /// state machines; AD-40's residency reasoning in
-    /// <see cref="CellTransit.BuildShadowCellSetFromParts"/>), the LAST-RESORT
-    /// fallback is the authored parent cell alone, and
-    /// <paramref name="usedFallback"/> reports it so the caller can count it.
-    /// </summary>
-    internal static IReadOnlyList<uint> ResolveIndoorStaticRenderCells(
-        in RenderProjectionRecord record,
-        Func<uint, (bool Found, IReadOnlyList<uint> Cells)> tryGetRetailCellArray,
-        out bool usedFallback)
-    {
-        ArgumentNullException.ThrowIfNull(tryGetRetailCellArray);
-
-        (bool found, IReadOnlyList<uint> cells) =
-            tryGetRetailCellArray(record.Source.LocalEntityId);
-        if (found)
-        {
-            usedFallback = false;
-            return cells;
-        }
-
-        usedFallback = true;
-        return record.Source.ParentCellId != 0u
-            ? new[] { record.Source.ParentCellId }
-            : Array.Empty<uint>();
-    }
-
-    /// <summary>
-    /// Campaign OVERHAUL S2 chunk 2: one authored outdoor static's
-    /// render-cell membership, borrowed from
-    /// <see cref="ShadowObjectRegistry.TryGetRetailCellArray"/> the same way
-    /// as <see cref="ResolveIndoorStaticRenderCells"/>. The fallback for an
-    /// entity the registry has not registered yet is today's collision-flood
-    /// <see cref="ShadowObjectRegistry.GetOwnerCells"/> answer (itself
-    /// possibly empty — <see cref="BucketOutdoorRecord"/> already carries its
-    /// own root-position-cell fallback for that case), counted the same way
-    /// as the indoor path via <paramref name="usedFallback"/>.
-    /// </summary>
-    internal static IReadOnlyList<uint> ResolveOutdoorStaticRenderCells(
-        in RenderProjectionRecord record,
-        Func<uint, (bool Found, IReadOnlyList<uint> Cells)> tryGetRetailCellArray,
-        Func<uint, IReadOnlyList<uint>> getOwnerCells,
-        out bool usedFallback)
-    {
-        ArgumentNullException.ThrowIfNull(tryGetRetailCellArray);
-        ArgumentNullException.ThrowIfNull(getOwnerCells);
-
-        (bool found, IReadOnlyList<uint> cells) =
-            tryGetRetailCellArray(record.Source.LocalEntityId);
-        if (found)
-        {
-            usedFallback = false;
-            return cells;
-        }
-
-        usedFallback = true;
-        return getOwnerCells(record.Source.LocalEntityId);
-    }
-
-    internal bool StaticBucketContains(uint cellId, uint sourceId) =>
-        _indoorByCell.TryGetValue(
-            cellId,
-            out List<RenderProjectionRecord>? records)
-        && records.Exists(record => record.Source.SourceId == sourceId);
-
-    /// <summary>
-    /// Buckets one authored indoor static into the render cell lists produced
-    /// by retail's cross-cell PartArray walk. Outdoor cells are routed to the
-    /// landscape turn because a visual part may cross an exit portal.
-    /// </summary>
-    internal static void BucketIndoorRecord(
-        in RenderProjectionRecord record,
-        IReadOnlyList<uint> renderCells,
-        Dictionary<uint, List<RenderProjectionRecord>> indoorBuckets,
-        Dictionary<uint, List<RenderProjectionRecord>> outdoorBuckets)
-    {
-        ArgumentNullException.ThrowIfNull(renderCells);
-        ArgumentNullException.ThrowIfNull(indoorBuckets);
-        ArgumentNullException.ThrowIfNull(outdoorBuckets);
-
-        bool added = false;
-        for (int i = 0; i < renderCells.Count; i++)
-        {
-            uint cellId = renderCells[i];
-            uint low = cellId & 0xFFFFu;
-            if (low is >= 1u and <= 64u)
-            {
-                AddToBucket(in record, cellId, outdoorBuckets);
-                added = true;
-            }
-            else if (low >= 0x100u)
-            {
-                AddToBucket(in record, cellId, indoorBuckets);
-                added = true;
-            }
-        }
-
-        if (!added && record.Source.ParentCellId != 0u)
-            AddToBucket(in record, record.Source.ParentCellId, indoorBuckets);
-    }
-
-    /// <summary>
-    /// Installs one live PartArray into every cell in retail's retained
-    /// <c>CELLARRAY</c>. Interior and landscape memberships can coexist while
-    /// crossing a building exit. If the collision owner is not registered yet
-    /// (or the object is a visual-only effect), the authored interior parent
-    /// or outdoor root-position cell remains the conservative fallback.
-    /// </summary>
-    internal static void BucketDynamicRecord(
-        in RenderProjectionRecord record,
-        IReadOnlyList<uint> shadowCells,
-        Dictionary<uint, List<RenderProjectionRecord>> indoorBuckets,
-        Dictionary<uint, List<RenderProjectionRecord>> outdoorBuckets,
-        int renderCenterLbX,
-        int renderCenterLbY)
-    {
-        ArgumentNullException.ThrowIfNull(shadowCells);
-        ArgumentNullException.ThrowIfNull(indoorBuckets);
-        ArgumentNullException.ThrowIfNull(outdoorBuckets);
-
-        bool added = false;
-        for (int i = 0; i < shadowCells.Count; i++)
-        {
-            uint cellId = shadowCells[i];
-            uint low = cellId & 0xFFFFu;
-            if (low is >= 1u and <= 64u)
-            {
-                AddToBucket(in record, cellId, outdoorBuckets);
-                added = true;
-            }
-            else if (low >= 0x100u)
-            {
-                AddToBucket(in record, cellId, indoorBuckets);
-                added = true;
-            }
-        }
-
-        if (added)
-            return;
-
-        uint parentLow = record.Source.ParentCellId & 0xFFFFu;
-        if (record.Source.ParentCellId != 0u && parentLow >= 0x100u)
-        {
-            AddToBucket(in record, record.Source.ParentCellId, indoorBuckets);
-            return;
-        }
-
-        uint outdoorCell = LandscapeCellId(
-            record.Transform.Position,
-            renderCenterLbX,
-            renderCenterLbY);
-        AddToBucket(in record, outdoorCell, outdoorBuckets);
-    }
-
-    /// <summary>
-    /// Installs one outdoor object's render shadow in every outdoor cell of
-    /// its authoritative physics <c>CELLARRAY</c>. This is retail's
-    /// <c>CPhysicsObj::add_shadows_to_cells</c> →
-    /// <c>CPartArray::AddPartsShadow</c> path: a large object straddling a
-    /// landblock edge must remain reachable when its origin cell leaves the
-    /// landscape walk. Objects without a collision registration (notably
-    /// short-lived visual effects) retain the root-position fallback.
-    /// </summary>
-    internal static void BucketOutdoorRecord(
-        in RenderProjectionRecord record,
-        IReadOnlyList<uint> shadowCells,
-        Dictionary<uint, List<RenderProjectionRecord>> buckets,
-        int renderCenterLbX,
-        int renderCenterLbY)
-    {
-        ArgumentNullException.ThrowIfNull(shadowCells);
-        ArgumentNullException.ThrowIfNull(buckets);
-
-        bool added = false;
-        for (int i = 0; i < shadowCells.Count; i++)
-        {
-            uint cellId = shadowCells[i];
-            uint cellIndex = cellId & 0xFFFFu;
-            if (cellIndex is < 1u or > 64u)
+            uint entityId = entries[i].EntityId;
+            if (havePrevious && entityId == previousEntityId)
                 continue;
+            previousEntityId = entityId;
+            havePrevious = true;
 
-            AddToBucket(in record, cellId, buckets);
-            added = true;
+            if (_scene.TryGetByLocalEntityId(entityId, out RenderProjectionRecord record)
+                && record.Source.SourceId == sourceId)
+            {
+                return true;
+            }
         }
-
-        if (!added)
-        {
-            uint cellId = LandscapeCellId(
-                record.Transform.Position,
-                renderCenterLbX,
-                renderCenterLbY);
-            AddToBucket(in record, cellId, buckets);
-        }
-    }
-
-    private static void AddToBucket(
-        in RenderProjectionRecord record,
-        uint cellId,
-        Dictionary<uint, List<RenderProjectionRecord>> buckets)
-    {
-        if (!buckets.TryGetValue(
-                cellId,
-                out List<RenderProjectionRecord>? bucket))
-        {
-            buckets[cellId] = bucket = new List<RenderProjectionRecord>();
-        }
-        bucket.Add(record);
-    }
-
-    /// <summary>The landscape cell owning a RENDER-ORIGIN-RELATIVE position
-    /// — retail's 24 m cell grid inside the 192 m landblock, producing the
-    /// same TRUE <c>(lb &amp; 0xFFFF0000) | (cellX*8 + cellY + 1)</c> encoding
-    /// the walk's landscape turn emits: the relative block index
-    /// (<c>floor(p/192)</c>) plus the streaming center recovers the true
-    /// landblock byte, because entity positions carry
-    /// <c>(lbX − CenterX)·192</c> world offsets
-    /// (<c>LandblockBuildFactory</c>'s <c>worldOffset</c>).</summary>
-    internal static uint LandscapeCellId(
-        Vector3 relativePosition, int renderCenterLbX, int renderCenterLbY)
-    {
-        int relBlockX = (int)MathF.Floor(relativePosition.X / 192f);
-        int relBlockY = (int)MathF.Floor(relativePosition.Y / 192f);
-        float localX = relativePosition.X - relBlockX * 192f;
-        float localY = relativePosition.Y - relBlockY * 192f;
-        int cellX = Math.Clamp((int)(localX / 24f), 0, 7);
-        int cellY = Math.Clamp((int)(localY / 24f), 0, 7);
-        uint landblock =
-            ((uint)(byte)(renderCenterLbX + relBlockX) << 24)
-            | ((uint)(byte)(renderCenterLbY + relBlockY) << 16);
-        return landblock | (uint)(cellX * 8 + cellY + 1);
+        return false;
     }
 
     public WalkFrameStaticRecords GetCellStatics(uint cellId)
     {
         if (_cellCache.TryGetValue(cellId, out WalkFrameStaticRecords cached))
             return cached;
-        WalkFrameStaticRecords records =
-            _indoorByCell.TryGetValue(cellId, out List<RenderProjectionRecord>? bucket)
-                && bucket.Count > 0
-                ? new WalkFrameStaticRecords(
-                    AppendToArena(CollectionsMarshal.AsSpan(bucket)), _tupleLandblockId)
-                : WalkFrameStaticRecords.Empty with { TupleLandblockId = _tupleLandblockId };
+        WalkFrameStaticRecords records = ResolveCellView(cellId, dynamic: false);
         EmitFacilityShadowProbe(records.Records, cellId, "static");
         _cellCache[cellId] = records;
         return records;
@@ -568,19 +256,112 @@ internal sealed class WalkProductionWorldData : IWalkFrameWorldData
     {
         if (_cellDynamicCache.TryGetValue(cellId, out WalkFrameStaticRecords cached))
             return cached;
-        WalkFrameStaticRecords records =
-            _indoorDynamicsByCell.TryGetValue(
-                cellId,
-                out List<RenderProjectionRecord>? bucket)
-            && bucket.Count > 0
-                ? new WalkFrameStaticRecords(
-                    AppendToArena(CollectionsMarshal.AsSpan(bucket)), _tupleLandblockId)
-                : WalkFrameStaticRecords.Empty with { TupleLandblockId = _tupleLandblockId };
+        WalkFrameStaticRecords records = ResolveCellView(cellId, dynamic: true);
         EmitFacilityShadowProbe(records.Records, cellId, "dynamic");
         _cellDynamicCache[cellId] = records;
         return records;
     }
 
+    public WalkFrameStaticRecords GetOutdoorStatics(uint cellId)
+    {
+        if (_outdoorMaterialized.TryGetValue(cellId, out WalkFrameStaticRecords cached))
+            return cached;
+        WalkFrameStaticRecords records = ResolveCellView(cellId, dynamic: false);
+        _outdoorMaterialized[cellId] = records;
+        return records;
+    }
+
+    public WalkFrameStaticRecords GetOutdoorDynamics(uint cellId)
+    {
+        if (_outdoorDynamicsMaterialized.TryGetValue(
+                cellId,
+                out WalkFrameStaticRecords cached))
+        {
+            return cached;
+        }
+
+        WalkFrameStaticRecords records = ResolveCellView(cellId, dynamic: true);
+        _outdoorDynamicsMaterialized[cellId] = records;
+        return records;
+    }
+
+    /// <summary>
+    /// Campaign OVERHAUL S2 chunk 5: one cell id's borrowed retail render
+    /// membership. Reads <see cref="ShadowObjectRegistry.GetRetailPartEntriesInCell"/>
+    /// — already in retail CELLARRAY-then-part-array insertion order —
+    /// collapses adjacent entries down to their distinct owning entity ids
+    /// (an entity's own entries for one cell are always written as one
+    /// contiguous run: <c>PublishRetailPartEntries</c> removes then re-adds a
+    /// whole entity's rows atomically, never interleaving two entities'
+    /// rows), resolves each id to its current projected record through
+    /// <see cref="RenderSceneQuery.TryGetByLocalEntityId"/>, and keeps only
+    /// the records matching <paramref name="dynamic"/>'s static/dynamic
+    /// class and excluding building shells. Indoor vs. outdoor is entirely a
+    /// property of WHICH cellId the caller passes (an indoor cell id's low
+    /// word is <c>&gt;= 0x100</c>, an outdoor one is in <c>[1, 64]</c> —
+    /// retail's own two id spaces): the registry already published this
+    /// entity into every crossed cell under its own true id, so no
+    /// additional indoor/outdoor dispatch is needed here.
+    /// </summary>
+    private WalkFrameStaticRecords ResolveCellView(uint cellId, bool dynamic)
+    {
+        IReadOnlyList<RetailPartEntry> entries =
+            _shadows.GetRetailPartEntriesInCell(cellId);
+        if (entries.Count == 0)
+            return WalkFrameStaticRecords.Empty with { TupleLandblockId = _tupleLandblockId };
+
+        int written = 0;
+        uint previousEntityId = 0;
+        bool havePrevious = false;
+        for (int i = 0; i < entries.Count; i++)
+        {
+            uint entityId = entries[i].EntityId;
+            if (havePrevious && entityId == previousEntityId)
+                continue;
+            previousEntityId = entityId;
+            havePrevious = true;
+
+            if (!_scene.TryGetByLocalEntityId(entityId, out RenderProjectionRecord record))
+            {
+                // The transient streaming window (this type's own doc
+                // comment): the registry already flooded this entity into
+                // its retail CELLARRAY, but the presentation journal has
+                // not applied its projected record yet this frame. Retail
+                // draws nothing for an object not yet in a cell — no second
+                // fallback.
+                if (_unregisteredEntitiesThisFrame.Add(entityId))
+                    UnregisteredRenderMembershipCount++;
+                continue;
+            }
+            if (record.EntityPayload.IsBuildingShell)
+                continue; // buildings draw at their own shell turn.
+            if (IsDynamicProjectionClass(record.ProjectionClass) != dynamic)
+                continue;
+
+            if (written == _cellViewScratch.Length)
+            {
+                var grown = new RenderProjectionRecord[_cellViewScratch.Length * 2];
+                Array.Copy(_cellViewScratch, grown, written);
+                _cellViewScratch = grown;
+            }
+            _cellViewScratch[written++] = record;
+        }
+
+        return written == 0
+            ? WalkFrameStaticRecords.Empty with { TupleLandblockId = _tupleLandblockId }
+            : new WalkFrameStaticRecords(
+                AppendToArena(_cellViewScratch.AsSpan(0, written)), _tupleLandblockId);
+    }
+
+    /// <summary>The same static/dynamic split <c>ArchRenderScene</c>'s own
+    /// internal indexing uses: a live dynamic root or an equipped child is
+    /// "dynamic"; every other <see cref="RenderProjectionClass"/> (including
+    /// <see cref="RenderProjectionClass.ActiveAnimatedStatic"/>) is
+    /// "static".</summary>
+    private static bool IsDynamicProjectionClass(RenderProjectionClass projectionClass) =>
+        projectionClass is RenderProjectionClass.LiveDynamicRoot
+            or RenderProjectionClass.EquippedChild;
+
     /// <summary>
     /// Facility Hub discriminator for retail's cross-cell render-shadow path.
     /// The scene query is currently keyed by authored parent cell, while retail
@@ -643,41 +424,6 @@ internal sealed class WalkProductionWorldData : IWalkFrameWorldData
         }
     }
 
-    public WalkFrameStaticRecords GetOutdoorStatics(uint cellId)
-    {
-        if (_outdoorMaterialized.TryGetValue(cellId, out WalkFrameStaticRecords cached))
-            return cached;
-        WalkFrameStaticRecords records =
-            _outdoorByCell.TryGetValue(cellId, out List<RenderProjectionRecord>? bucket)
-                && bucket.Count > 0
-                ? new WalkFrameStaticRecords(
-                    AppendToArena(CollectionsMarshal.AsSpan(bucket)), _tupleLandblockId)
-                : WalkFrameStaticRecords.Empty with { TupleLandblockId = _tupleLandblockId };
-        _outdoorMaterialized[cellId] = records;
-        return records;
-    }
-
-    public WalkFrameStaticRecords GetOutdoorDynamics(uint cellId)
-    {
-        if (_outdoorDynamicsMaterialized.TryGetValue(
-                cellId,
-                out WalkFrameStaticRecords cached))
-        {
-            return cached;
-        }
-
-        WalkFrameStaticRecords records =
-            _outdoorDynamicsByCell.TryGetValue(
-                cellId,
-                out List<RenderProjectionRecord>? bucket)
-                && bucket.Count > 0
-                ? new WalkFrameStaticRecords(
-                    AppendToArena(CollectionsMarshal.AsSpan(bucket)), _tupleLandblockId)
-                : WalkFrameStaticRecords.Empty with { TupleLandblockId = _tupleLandblockId };
-        _outdoorDynamicsMaterialized[cellId] = records;
-        return records;
-    }
-
     public WalkFrameStaticRecords GetBuildingShellStatics(WalkBuilding building)
     {
         uint anchor = BuildingShellBucketCellId(building);
@@ -698,7 +444,7 @@ internal sealed class WalkProductionWorldData : IWalkFrameWorldData
     /// <summary>Copies <paramref name="source"/> into <see cref="_arena"/> at
     /// its current length, growing the arena first if needed (doubling, or
     /// exactly enough for an unusually large sweep — the same growth shape
-    /// <see cref="_sweepScratch"/>/<see cref="_cellScratch"/> already use),
+    /// <see cref="_sweepScratch"/>/<see cref="_cellViewScratch"/> already use),
     /// and returns the segment the copy landed in. A prior frame's growth can
     /// leave an earlier-returned segment pointing at a retired backing array
     /// — harmless, since that array's content stays valid and nothing reads

src/AcDream.App/Streaming/LandblockPhysicsPublisher.cs

@@ -1084,6 +1084,34 @@ public sealed class LandblockPhysicsPublisher
             }
         }
 
+        // Campaign OVERHAUL S2 chunk 5 closeout: a DAT static with visual
+        // parts but NO collision geometry (decorative trim, wall panels,
+        // banners) is still a CPhysicsObj retail floods into its cells —
+        // calc_cross_cells_static (0x00515160) takes the find_bbox_cell_list
+        // route over the part array when there is no cylsphere, and
+        // add_shadows_to_cells (0x00514ae0) publishes AddPartsShadow rows
+        // for every part regardless of collision. Since chunk 5 the walk
+        // draws ONLY what the registry flooded (the parent-cell fallback is
+        // deleted), so such a static must register render-only here or it
+        // vanishes (G2 self-gate: the Facility Hub's purple-lit wall panels).
+        if (entityBspCount == 0 && entityCylinderCount == 0
+            && partArray.Count > 0)
+        {
+            publication.StagingEngine.ShadowObjects.RegisterMultiPart(
+                entity.Id,
+                entity.Position,
+                entity.Rotation,
+                Array.Empty<ShadowShape>(),
+                0u,
+                EntityCollisionFlags.None,
+                publication.Origin.X,
+                publication.Origin.Y,
+                landblock.LandblockId,
+                seedCellId: entity.ParentCellId ?? 0u,
+                isStatic: true,
+                partArray: partArray);
+        }
+
         if (entityBspCount > 0)
             publication.BspOwnerCount++;
         if (entityCylinderCount > 0)

src/AcDream.Content/LandblockPhysicsContentBuilder.cs

@@ -650,6 +650,8 @@ public static class LandblockPhysicsContentBuilder
                     entity.SourceGfxObjOrSetupId);
             if (setup is null)
             {
+                RegisterRenderOnlyStatic(
+                    engine, entity, partArray, landblock, origin);
                 noCollision++;
                 continue;
             }
@@ -710,6 +712,8 @@ public static class LandblockPhysicsContentBuilder
             // LiveEntityCollisionBuilder's remarks for the retail anchor.
             if (setupShapes.Count == 0)
             {
+                RegisterRenderOnlyStatic(
+                    engine, entity, partArray, landblock, origin);
                 noCollision++;
                 continue;
             }
@@ -744,6 +748,41 @@ public static class LandblockPhysicsContentBuilder
             noCollision);
     }
 
+    /// <summary>
+    /// Campaign OVERHAUL S2 chunk 5 closeout: a DAT static with visual parts
+    /// but no collision geometry is still a <c>CPhysicsObj</c> retail floods
+    /// into its cells — <c>calc_cross_cells_static</c> (0x00515160) takes the
+    /// <c>find_bbox_cell_list</c> route over the part array when there is no
+    /// cylsphere, and <c>add_shadows_to_cells</c> (0x00514ae0) publishes
+    /// <c>AddPartsShadow</c> rows for every part regardless of collision.
+    /// The walk draws only what the registry flooded, so the static registers
+    /// render-only (empty collision shapes, whole part array); a static with
+    /// no visual part either stays unregistered.
+    /// </summary>
+    private static void RegisterRenderOnlyStatic(
+        PhysicsEngine engine,
+        WorldEntity entity,
+        IReadOnlyList<ShadowShape> partArray,
+        LoadedLandblock landblock,
+        Vector3 origin)
+    {
+        if (partArray.Count == 0)
+            return;
+        engine.ShadowObjects.RegisterMultiPart(
+            entity.Id,
+            entity.Position,
+            entity.Rotation,
+            Array.Empty<ShadowShape>(),
+            0u,
+            EntityCollisionFlags.None,
+            worldOffsetX: origin.X,
+            worldOffsetY: origin.Y,
+            landblockId: landblock.LandblockId,
+            seedCellId: entity.ParentCellId ?? 0u,
+            isStatic: true,
+            partArray: partArray);
+    }
+
     private static T Require<T>(
         PreparedCollisionReadResult<T> result,
         string kind,

src/AcDream.Core/Physics/ShadowObjectRegistry.cs

@@ -506,6 +506,20 @@ public sealed class ShadowObjectRegistry
         RetailCellArrayRoute route,
         IReadOnlyList<ShadowShape> partArray)
     {
+        // Campaign OVERHAUL S2 review fix (arch F3): retail never floods an
+        // attached child — add_shadows_to_cells (0x00514ae0) passes the
+        // ROOT's CELLARRAY down through `children`. A re-registration or move
+        // of an entity that is currently attached (an equipped item's
+        // appearance update through ReplaceMultiPartPayload/RegisterMultiPart)
+        // only refreshes the part array it inherits the root's cells with.
+        if (_childParent.ContainsKey(entityId))
+        {
+            if (partArray.Count != 0)
+                _childPartArrays[entityId] = partArray;
+            _retailCellArrayRoutes[entityId] = route;
+            PublishChildEntries(entityId);
+            return;
+        }
         if (_retailCellArrays.TryGetValue(entityId, out List<uint>? previousCells))
         {
             RemoveRetailPartEntriesFromCells(entityId, previousCells);
@@ -604,13 +618,71 @@ public sealed class ShadowObjectRegistry
                     cellIds[i],
                     out List<RetailPartEntry>? entries))
             {
-                entries.RemoveAll(e => e.EntityId == entityId);
+                RemoveOwnerPartRows(entries, entityId);
                 if (entries.Count == 0)
                     _retailPartEntriesByCell.Remove(cellIds[i]);
             }
         }
     }
 
+    /// <summary>The <see cref="RemoveOwnerRows"/> twin for the retail part
+    /// rows: a reverse index loop, no closure — this runs per cell on every
+    /// accepted move (arch review F7).</summary>
+    private static void RemoveOwnerPartRows(
+        List<RetailPartEntry> entries,
+        uint entityId)
+    {
+        for (int index = entries.Count - 1; index >= 0; index--)
+        {
+            if (entries[index].EntityId == entityId)
+                entries.RemoveAt(index);
+        }
+    }
+
+    private static ShadowEntry[] CollectOwnerRows(
+        List<ShadowEntry> entries,
+        uint entityId)
+    {
+        int count = 0;
+        for (int index = 0; index < entries.Count; index++)
+        {
+            if (entries[index].EntityId == entityId)
+                count++;
+        }
+        if (count == 0)
+            return Array.Empty<ShadowEntry>();
+        var rows = new ShadowEntry[count];
+        int written = 0;
+        for (int index = 0; index < entries.Count; index++)
+        {
+            if (entries[index].EntityId == entityId)
+                rows[written++] = entries[index];
+        }
+        return rows;
+    }
+
+    private static RetailPartEntry[] CollectOwnerPartRows(
+        List<RetailPartEntry> entries,
+        uint entityId)
+    {
+        int count = 0;
+        for (int index = 0; index < entries.Count; index++)
+        {
+            if (entries[index].EntityId == entityId)
+                count++;
+        }
+        if (count == 0)
+            return Array.Empty<RetailPartEntry>();
+        var rows = new RetailPartEntry[count];
+        int written = 0;
+        for (int index = 0; index < entries.Count; index++)
+        {
+            if (entries[index].EntityId == entityId)
+                rows[written++] = entries[index];
+        }
+        return rows;
+    }
+
     /// <summary>
     /// Publishes retail's <c>CPartArray::AddPartsShadow</c> (0x00517e40) rows
     /// for one entity: for every cell in <paramref name="orderedCells"/>, in
@@ -742,6 +814,12 @@ public sealed class ShadowObjectRegistry
         _childPartArrays[childEntityId] = childPartArray;
 
         PublishChildEntries(childEntityId);
+        // Campaign OVERHAUL S2 review fix (arch F2): an attach mutates shared
+        // per-cell rows, so it must invalidate any prepared SetPosition commit
+        // whose captured cell lists predate it (IsPreparedSetPositionCurrent
+        // keys on the mutation revision) — otherwise that commit's wholesale
+        // list install silently drops the child's rows.
+        AdvanceMutationRevision();
         return true;
     }
 
@@ -786,6 +864,7 @@ public sealed class ShadowObjectRegistry
             if (siblings.Count == 0)
                 _parentChildren.Remove(parentId);
         }
+        AdvanceMutationRevision(); // see AttachChild (arch F2)
         return true;
     }
 
@@ -1041,7 +1120,32 @@ public sealed class ShadowObjectRegistry
         bool publishMutation = true,
         IReadOnlyList<ShadowShape>? partArray = null)
     {
-        if (shapes.Count == 0) { Deregister(entityId); return; }
+        if (shapes.Count == 0)
+        {
+            // Campaign OVERHAUL S2 chunk 5 (item B): a live entity whose
+            // collision dispatch produced NO shapes (LiveEntityCollisionBuilder.
+            // Build's Shapes==[]) but whose Setup still has visual parts — the
+            // retail short-lived spell/visual effect-object case — is NOT a
+            // deregistration. Contract B's render membership
+            // (CPartArray::AddPartsShadow) does not require a successful
+            // collision dispatch; only the collision-side shadow_object_list
+            // does. Route it to the render-only registration path instead.
+            // A caller with no part array either (every pre-chunk-5 test
+            // fixture, and any genuinely shapeless entity) keeps the exact
+            // prior behavior: deregister.
+            if (partArray is { Count: > 0 })
+            {
+                RegisterRenderOnly(
+                    entityId, entityWorldPos, entityWorldRot, state, flags,
+                    worldOffsetX, worldOffsetY, landblockId, seedCellId,
+                    isStatic, publishMutation, partArray);
+            }
+            else
+            {
+                Deregister(entityId);
+            }
+            return;
+        }
 
         // Flood FIRST — keep-when-empty, see Register.
         uint seed = seedCellId != 0u
@@ -1157,6 +1261,79 @@ public sealed class ShadowObjectRegistry
         }
     }
 
+    /// <summary>
+    /// Campaign OVERHAUL S2 chunk 5 (item B): registers a live entity that
+    /// has NO collision shapes at all but DOES have a visual part array — the
+    /// retail short-lived spell/visual effect-object case
+    /// (<c>LiveEntityCollisionBuilder.Build</c> returns
+    /// <c>Shapes = []</c>, <c>RenderParts != []</c>). Retail's
+    /// <c>calc_cross_cells_static</c> dispatch (Contract A) never
+    /// special-cases "no collision shapes": the cylsphere-vs-bbox TEST reads
+    /// the collision shapes (none here, so the test is always false) and the
+    /// flood unconditionally falls through to the bbox route over the WHOLE
+    /// part array (<see cref="ComputeContractACellArray"/> with an empty
+    /// <c>collisionShapes</c> list). The entity therefore gets an exact
+    /// retail CELLARRAY and <see cref="RetailPartEntry"/> rows exactly like a
+    /// colliding entity, but never a <see cref="ShadowEntry"/> collision row
+    /// anywhere — Contract B's <c>shadow_object_list</c> receives one entry
+    /// per CELLARRAY cell only when the object HAS a part to shadow there;
+    /// this object contributes to <c>shadow_part_list</c> only.
+    /// <para>
+    /// <see cref="_entityShapes"/> is retained as an EMPTY (not absent) list
+    /// so every existing multi-part-dispatch site
+    /// (<see cref="UpdatePosition"/>, <see cref="ReplacePositionRows"/>,
+    /// <see cref="RefloodOwnerForLandblock"/>) takes the "multi-part, zero
+    /// shapes" branch on a later move/reflood instead of falling back to the
+    /// single-shape <see cref="Register"/> path or synthesizing a bogus
+    /// zero-radius shadow entry.
+    /// </para>
+    /// </summary>
+    private void RegisterRenderOnly(
+        uint entityId,
+        Vector3 entityWorldPos,
+        Quaternion entityWorldRot,
+        uint state,
+        EntityCollisionFlags flags,
+        float worldOffsetX,
+        float worldOffsetY,
+        uint landblockId,
+        uint seedCellId,
+        bool isStatic,
+        bool publishMutation,
+        IReadOnlyList<ShadowShape> partArray)
+    {
+        // Flood FIRST — keep-when-empty, see Register.
+        uint seed = seedCellId != 0u
+            ? seedCellId
+            : DeriveOutdoorSeed(entityWorldPos, worldOffsetX, worldOffsetY, landblockId);
+        if (seed == 0u) return;
+
+        (IReadOnlyList<uint> cellSet, RetailCellArrayRoute retailRoute) =
+            ComputeContractACellArray(
+                seed,
+                entityWorldPos,
+                entityWorldRot,
+                state,
+                collisionShapes: Array.Empty<ShadowShape>(),
+                partArray,
+                isStatic);
+        if (cellSet.Count == 0) return; // keep-when-empty (pc:283540).
+
+        DeregisterCore(entityId, publishMutation: false);
+        _entityShapes[entityId] = Array.Empty<ShadowShape>();
+        _entityReg[entityId] = new RegistrationRecord(
+            seed, entityWorldPos, entityWorldRot, state, flags, isStatic,
+            IsMultiPart: true, GfxObjId: 0u, Radius: 0f,
+            CollisionType: ShadowCollisionType.BSP, CylHeight: 0f, Scale: 1f);
+        if (publishMutation)
+            BumpOwnerVersion(entityId);
+        else
+            RefreshOwnerPrefixIndex(entityId);
+
+        _entityRetailPartArrays[entityId] = partArray;
+        PublishRetailCellArray(entityId, cellSet, retailRoute, partArray);
+    }
+
     /// <summary>
     /// Replaces an existing live PartArray collision payload in its current
     /// shadow-cell membership. Retail <c>CPartArray::SetPart</c> changes the
@@ -1183,7 +1360,11 @@ public sealed class ShadowObjectRegistry
         if (!_entityReg.TryGetValue(entityId, out RegistrationRecord? prior)
             || !prior.IsMultiPart)
         {
-            if (shapes.Count == 0)
+            // Campaign OVERHAUL S2 chunk 5 (item B): a not-yet-registered
+            // entity with no collision shapes but a real part array still
+            // needs registering (render-only) — RegisterMultiPart's own
+            // shapes.Count==0 branch now handles that dispatch.
+            if (shapes.Count == 0 && (partArray is null || partArray.Count == 0))
                 return;
             RegisterMultiPart(
                 entityId,
@@ -1217,7 +1398,10 @@ public sealed class ShadowObjectRegistry
         // this replaces the retained part array WITHOUT re-flooding. It
         // reuses the CURRENT retail CELLARRAY (if any) and only rewrites
         // which parts occupy it, mirroring the collision payload swap below.
-        if (partArray is not null)
+        // Arch review F9: a non-null but EMPTY part array is "no part to
+        // shadow" — treated exactly like the null case rather than leaving a
+        // cell array with no drawable rows behind.
+        if (partArray is { Count: > 0 })
         {
             _entityRetailPartArrays[entityId] = partArray;
             if (_retailCellArrays.TryGetValue(entityId, out List<uint>? retailCells)
@@ -2270,6 +2454,37 @@ public sealed class ShadowObjectRegistry
             return;
         }
 
+        // Campaign OVERHAUL S2 review fix (retail F3): a RENDER-ONLY owner
+        // (part array, no collision shapes, hence never any retained
+        // collision cells) still moves in retail — add_shadows_to_cells
+        // (0x00514ae0) adds the CShadowObj unconditionally (pc:282856) and
+        // gates only AddPartsShadow on part_array != 0, so a shapeless
+        // visual object keeps a cell array it travels with. Its transition
+        // carries no sphere, so that array is its destination cell alone
+        // (num_cells == 1 → AddPartsShadow without clip planes). AD-117
+        // records the single-cell reading until a cdb trace pins the
+        // zero-sphere transition's exact cell list.
+        if (!_entityToCells.ContainsKey(entityId)
+            && !_suspendedEntityCells.ContainsKey(entityId)
+            && seedCellId != 0u
+            && _entityRetailPartArrays.TryGetValue(
+                entityId,
+                out IReadOnlyList<ShadowShape>? renderPartArray)
+            && renderPartArray.Count != 0)
+        {
+            _suspendedEntities.Remove(entityId);
+            _entityReg[entityId] = registration with
+            {
+                SeedCellId = seedCellId,
+                EntityWorldPos = worldPosition,
+                EntityWorldRot = worldRotation,
+            };
+            _singleCellScratch[0] = seedCellId;
+            PublishRetailProductFromExactCells(entityId, _singleCellScratch);
+            BumpOwnerVersion(entityId);
+            return;
+        }
+
         // Campaign OVERHAUL S2 chunk 4: retail's keep-when-empty gate
         // (pc:283540) reached its terminal case — no retained collision
         // cells at all to republish from — so BOTH products stay exactly as
@@ -2285,6 +2500,8 @@ public sealed class ShadowObjectRegistry
         BumpOwnerVersion(entityId);
     }
 
+    private readonly uint[] _singleCellScratch = new uint[1];
+
     private void ReplacePositionRows(
         uint entityId,
         RegistrationRecord registration,
@@ -2326,12 +2543,12 @@ public sealed class ShadowObjectRegistry
             exactCells.Add(cellId);
         }
 
-        if (registration.IsMultiPart
-            && _entityShapes.TryGetValue(
-                entityId,
-                out IReadOnlyList<ShadowShape>? shapes))
+        IReadOnlyList<ShadowShape>? shapes = null;
+        bool isMultiPartDispatch = registration.IsMultiPart
+            && _entityShapes.TryGetValue(entityId, out shapes);
+        if (isMultiPartDispatch)
         {
-            foreach (ShadowShape shape in shapes)
+            foreach (ShadowShape shape in shapes!)
             {
                 Vector3 partWorldPosition = worldPosition
                     + Vector3.Transform(shape.LocalPosition, worldRotation);
@@ -2371,7 +2588,15 @@ public sealed class ShadowObjectRegistry
                 AddEntryToCell(entry, exactCells[index]);
         }
 
-        if (exactCells.Count == 0)
+        // Campaign OVERHAUL S2 chunk 5 (item B): a render-only multi-part
+        // entity (registration.IsMultiPart with an EMPTY retained shapes
+        // list — see RegisterRenderOnly) writes NO ShadowEntry rows above.
+        // _entityToCells must stay absent for it too, or a consumer reading
+        // it (GetOwnerCells, DeregisterCore's cleanup walk) would see cell
+        // ids that carry no actual collision row — a membership claim this
+        // registry never backs with a shadow_object_list entry.
+        bool wroteCollisionEntries = !isMultiPartDispatch || shapes!.Count != 0;
+        if (exactCells.Count == 0 || !wroteCollisionEntries)
             _entityToCells.Remove(entityId);
         else
             _entityToCells[entityId] = exactCells;
@@ -2414,11 +2639,26 @@ public sealed class ShadowObjectRegistry
             foreach (uint cellId in cellIds)
             {
                 if (_cells.TryGetValue(cellId, out var list))
-                    list.RemoveAll(entry => entry.EntityId == entityId);
+                    RemoveOwnerRows(list, entityId);
             }
             _entityToCells.Remove(entityId);
         }
 
+        // Campaign OVERHAUL S2 review fix (arch F1 / retail F2): retail's
+        // remove_shadows_from_cells (0x00511230) is ONE transaction over both
+        // products — per shadow cell it calls CObjCell::remove_shadow_object
+        // AND CPartArray::RemoveParts, then recurses through children. A
+        // suspended object therefore has no render membership either; the
+        // retained part array and route survive so the un-suspending move
+        // (ReplacePositionRows → PublishRetailProductFromExactCells)
+        // republishes from the transition's cells.
+        if (_retailCellArrays.TryGetValue(entityId, out List<uint>? retailCells))
+        {
+            RemoveRetailPartEntriesFromCells(entityId, retailCells);
+            _retailCellArrays.Remove(entityId);
+            RepublishAttachedChildren(entityId);
+        }
+
         _suspendedEntities.Add(entityId);
         BumpOwnerVersion(entityId);
         return true;
@@ -2502,6 +2742,19 @@ public sealed class ShadowObjectRegistry
         _withdrawnPrefixesByOwner.TryGetValue(
             entityId,
             out var withdrawnBeforeReflood);
+
+        // Campaign OVERHAUL S2 chunk 5 closeout: a reflood is retail's
+        // recalc_cross_cells over the SAME CPartArray — the render product
+        // (retail cell array + AddPartsShadow rows) is recomputed from the
+        // retained part array exactly like the movement path above does.
+        // Without this the walk (which reads ONLY GetRetailPartEntriesInCell
+        // since chunk 5) lost every reflooded owner: landblock replacement
+        // commits (PhysicsEngine.ApplyCommittedOwnerReplacement) and the
+        // Content builder's post-publication reflood both come through here.
+        _entityRetailPartArrays.TryGetValue(
+            entityId,
+            out IReadOnlyList<ShadowShape>? retainedPartArray);
+
         if (reg.IsMultiPart
             && _entityShapes.TryGetValue(entityId, out var shapes))
         {
@@ -2517,7 +2770,8 @@ public sealed class ShadowObjectRegistry
                 lbPrefix,
                 reg.SeedCellId,
                 reg.IsStatic,
-                publishMutation: false);
+                publishMutation: false,
+                partArray: retainedPartArray);
         }
         else
         {
@@ -2537,7 +2791,8 @@ public sealed class ShadowObjectRegistry
                 reg.Flags,
                 reg.SeedCellId,
                 reg.IsStatic,
-                publishMutation: false);
+                publishMutation: false,
+                partArray: retainedPartArray);
         }
 
         // Register is also the authoritative movement/replacement API and
@@ -2870,10 +3125,69 @@ public sealed class ShadowObjectRegistry
                 _withdrawnPrefixesByOwner.Remove(eid);
             }
         }
+        // Campaign OVERHAUL S2 review fix (arch F4 / retail F4): the retail
+        // render product ends with the landblock too — remove_shadows_from_
+        // cells (0x00511230) never removes the CShadowObj without the
+        // AddPartsShadow rows. Every part row in the prefix's cells goes;
+        // each owner's cell array loses those cells (a dynamic owner keeps
+        // its part array for the reload reflood, a static owner ends here —
+        // including a render-only static, which has no collision cells and
+        // so was invisible to the loops above).
+        RemoveRetailProductForPrefix(lbPrefix, touchedOwners);
         foreach (uint entityId in touchedOwners)
             BumpOwnerVersion(entityId);
     }
 
+    private readonly List<uint> _prefixRemovalScratch = new();
+
+    private void RemoveRetailProductForPrefix(
+        uint lbPrefix,
+        HashSet<uint> touchedOwners)
+    {
+        _prefixRemovalScratch.Clear();
+        foreach (uint cellId in _retailPartEntriesByCell.Keys)
+        {
+            if ((cellId & 0xFFFF0000u) == lbPrefix)
+                _prefixRemovalScratch.Add(cellId);
+        }
+        for (int i = 0; i < _prefixRemovalScratch.Count; i++)
+            _retailPartEntriesByCell.Remove(_prefixRemovalScratch[i]);
+
+        _prefixRemovalScratch.Clear();
+        foreach (var (ownerId, cells) in _retailCellArrays)
+        {
+            for (int i = cells.Count - 1; i >= 0; i--)
+            {
+                if ((cells[i] & 0xFFFF0000u) == lbPrefix)
+                {
+                    cells.RemoveAt(i);
+                    touchedOwners.Add(ownerId);
+                }
+            }
+            if (cells.Count == 0)
+                _prefixRemovalScratch.Add(ownerId);
+        }
+        for (int i = 0; i < _prefixRemovalScratch.Count; i++)
+        {
+            uint ownerId = _prefixRemovalScratch[i];
+            _retailCellArrays.Remove(ownerId);
+            bool endsWithLandblock =
+                !_entityReg.TryGetValue(ownerId, out RegistrationRecord? registration)
+                || registration.IsStatic;
+            if (!endsWithLandblock)
+                continue;
+            _retailCellArrayRoutes.Remove(ownerId);
+            _entityRetailPartArrays.Remove(ownerId);
+            // A render-only static never had collision cells, so the static
+            // retirement loop above could not reach its registration.
+            _entityShapes.Remove(ownerId);
+            _entityReg.Remove(ownerId);
+            _suspendedEntities.Remove(ownerId);
+            _suspendedEntityCells.Remove(ownerId);
+            _withdrawnPrefixesByOwner.Remove(ownerId);
+        }
+    }
+
     /// <summary>
     /// Retires one logical owner's rows from a streamed-out prefix. This is
     /// the owner-granular form used by the collision-generation retirement
@@ -2895,10 +3209,39 @@ public sealed class ShadowObjectRegistry
             AdvanceMutationRevision();
             return;
         }
-        if (!_entityToCells.TryGetValue(entityId, out List<uint>? cells))
-            return;
-
         bool touched = false;
+        // Campaign OVERHAUL S2 review fix (arch F4 / retail F4): the owner's
+        // retail part rows leave the retired prefix's cells together with
+        // its collision rows (remove_shadows_from_cells 0x00511230 removes
+        // both per cell); the part array stays for the reload reflood.
+        if (_retailCellArrays.TryGetValue(entityId, out List<uint>? retailCells))
+        {
+            for (int index = retailCells.Count - 1; index >= 0; index--)
+            {
+                uint cellId = retailCells[index];
+                if ((cellId & 0xFFFF0000u) != prefix)
+                    continue;
+                touched = true;
+                retailCells.RemoveAt(index);
+                if (_retailPartEntriesByCell.TryGetValue(
+                        cellId,
+                        out List<RetailPartEntry>? partRows))
+                {
+                    RemoveOwnerPartRows(partRows, entityId);
+                    if (partRows.Count == 0)
+                        _retailPartEntriesByCell.Remove(cellId);
+                }
+            }
+            if (retailCells.Count == 0)
+                _retailCellArrays.Remove(entityId);
+        }
+        if (!_entityToCells.TryGetValue(entityId, out List<uint>? cells))
+        {
+            if (touched)
+                BumpOwnerVersion(entityId);
+            return;
+        }
+
         for (int index = cells.Count - 1; index >= 0; index--)
         {
             uint cellId = cells[index];
@@ -3311,8 +3654,7 @@ public sealed class ShadowObjectRegistry
                 {
                     rows.Add(new PreparedShadowCellRows(
                         cellId,
-                        entries.Where(entry => entry.EntityId == entityId)
-                            .ToArray()));
+                        CollectOwnerRows(entries, entityId)));
                 }
             }
         }
@@ -3341,8 +3683,7 @@ public sealed class ShadowObjectRegistry
                 {
                     retailRows.Add(new PreparedShadowRetailPartRows(
                         cellId,
-                        entries.Where(entry => entry.EntityId == entityId)
-                            .ToArray()));
+                        CollectOwnerPartRows(entries, entityId)));
                 }
             }
         }

src/AcDream.Runtime/Physics/LiveEntityCollisionBuilder.cs

@@ -220,19 +220,15 @@ internal sealed class LiveEntityCollisionBuilder
             effectivePartGfxObjIds: effectivePartGfxObjIds,
             physicsBspBounds: _physicsBspBounds);
 
-        if (shapes.Count == 0 && !retainEmptyPayload)
-            return null;
-
-        EntityCollisionFlags flags = EntityCollisionFlags.HasWeenie;
-        if (spawn.ObjectDescriptionFlags is { } descriptionFlags)
-            flags |= EntityCollisionFlagsExt.FromPwdBitfield(descriptionFlags);
-        if (spawn.ItemType == (uint)ItemType.Creature)
-            flags |= EntityCollisionFlags.IsCreature;
-
-        // Campaign OVERHAUL S2 chunk 1b: retail's WHOLE visual part array —
-        // every Setup part, colliding or not — beside the BSP-exclusive
-        // `shapes` collision dispatch above. A side product only; nothing
-        // consumes it yet.
+        // Campaign OVERHAUL S2 chunk 5 (item B): retail's WHOLE visual part
+        // array — every Setup part, colliding or not — computed BEFORE the
+        // empty-shapes gate below. A live entity whose Setup carries visual
+        // parts but no collision geometry at all (a short-lived spell/visual
+        // effect object) must still register for render: Contract B's
+        // CPartArray::AddPartsShadow membership is not gated on a successful
+        // collision-shape dispatch, only on a non-null part array. Distinct
+        // from `shapes`, which stays the BSP-exclusive COLLISION dispatch
+        // (AP-152).
         IReadOnlyList<ShadowShape> renderParts = ShadowShapeBuilder.FromSetupRenderParts(
             setup,
             scale,
@@ -241,6 +237,21 @@ internal sealed class LiveEntityCollisionBuilder
             _getGfxObj,
             _getVisualBounds);
 
+        // Campaign OVERHAUL S2 chunk 5: a Setup with NEITHER a collision
+        // shape NOR a visual part yields no registration at all — retail
+        // synthesizes nothing for a truly shapeless object (see this
+        // method's class remarks). `retainEmptyPayload` (ObjDesc updates
+        // that must be able to clear a prior collision payload down to
+        // nothing) still forces a registration through even here.
+        if (shapes.Count == 0 && renderParts.Count == 0 && !retainEmptyPayload)
+            return null;
+
+        EntityCollisionFlags flags = EntityCollisionFlags.HasWeenie;
+        if (spawn.ObjectDescriptionFlags is { } descriptionFlags)
+            flags |= EntityCollisionFlagsExt.FromPwdBitfield(descriptionFlags);
+        if (spawn.ItemType == (uint)ItemType.Creature)
+            flags |= EntityCollisionFlags.IsCreature;
+
         return new LiveEntityCollisionRegistration(
             entity.Id,
             entity.SourceGfxObjOrSetupId,

tests/AcDream.App.Tests/Physics/LiveEntityCollisionBuilderTests.cs

@@ -155,6 +155,78 @@ public sealed class LiveEntityCollisionBuilderTests
         Assert.Equal(part, shape.GfxObjId);
     }
 
+    /// <summary>
+    /// Campaign OVERHAUL S2 chunk 5 (item B): a short-lived spell/visual
+    /// effect object's Setup can carry a visual part with no physics BSP and
+    /// no CylSpheres/Spheres — retail's <c>FindObjCollisions</c> synthesizes
+    /// no COLLISION shape for such a part (this file's own
+    /// <see cref="ShapelessSetupWithRadius_ProducesNoRegistration"/> remark),
+    /// but the part is still a real visual part
+    /// <c>CPartArray::AddPartsShadow</c> must register for render (Contract
+    /// B). <see cref="LiveEntityCollisionBuilder.Build"/> must not collapse
+    /// this case to "no registration at all" just because the COLLISION
+    /// dispatch came up empty — it must still return a registration whose
+    /// <c>RenderParts</c> carries the part, and
+    /// <see cref="LiveEntityCollisionBuilder.Register"/> (the exact call
+    /// <c>DatLiveEntityProjectionMaterializer</c> makes) must register it
+    /// render-only: a real retail CELLARRAY with per-cell
+    /// <c>RetailPartEntry</c> rows, but NO collision row anywhere.
+    /// </summary>
+    [Fact]
+    public void Build_PartWithNoCollisionButResolvableVisualBounds_RegistersRenderOnly()
+    {
+        const uint part = 0x0100BEEFu;
+        var setup = new Setup();
+        setup.Parts.Add(part);
+        WorldSession.EntitySpawn spawn = Spawn(scale: 1f);
+        var record = LiveEntityTestFixture.CreateExactProjectionRecord(spawn);
+        WorldEntity entity = Entity();
+        record.WorldEntity = entity;
+        var builder = new LiveEntityCollisionBuilder(
+            physicsBspBounds: _ => null,
+            PoseResolver(),
+            getGfxObj: _ => null,
+            getVisualBounds: id => id == part
+                ? new GfxObjVisualBounds
+                {
+                    Min = new Vector3(-1f, -1f, -1f),
+                    Max = new Vector3(1f, 1f, 1f),
+                    Center = Vector3.Zero,
+                    Radius = 1.5f,
+                    HalfExtents = new Vector3(1f, 1f, 1f),
+                }
+                : null);
+
+        LiveEntityCollisionRegistration registration = Assert.IsType<LiveEntityCollisionRegistration>(
+            builder.Build(
+                entity,
+                setup,
+                [part],
+                spawn,
+                record.ServerGuid,
+                record.Generation,
+                record.WorldEntity!,
+                record.FinalPhysicsState,
+                Vector3.Zero));
+
+        Assert.Empty(registration.Shapes);
+        ShadowShape renderPart = Assert.Single(registration.RenderParts);
+        Assert.Equal(part, renderPart.GfxObjId);
+
+        var registry = new ShadowObjectRegistry();
+        LiveEntityCollisionBuilder.Register(registry, registration);
+
+        Assert.True(
+            registry.TryGetRetailCellArray(entity.Id, out IReadOnlyList<uint> cells));
+        Assert.NotEmpty(cells);
+        Assert.Empty(registry.GetOwnerCells(entity.Id));
+        var entries = registry.GetRetailPartEntriesInCell(cells[0])
+            .Where(e => e.EntityId == entity.Id)
+            .ToList();
+        Assert.Single(entries);
+        Assert.Equal(part, entries[0].GfxObjId);
+    }
+
     /// <summary>
     /// AP-152. Every other fixture in this file is primitive-only or BSP-only,
     /// so nothing at the App layer used to exercise the CylSphere+BSP

tests/AcDream.App.Tests/Rendering/ArchRenderSceneTests.cs

@@ -520,13 +520,6 @@ public sealed class ArchRenderSceneTests
                 LightCandidate: 1,
                 Dirty: 6),
             query.IndexCounts);
-        Assert.Equal(1, query.GetCellStaticCount(indoorCell));
-        Assert.Equal(1, query.GetCellDynamicCount(indoorCell));
-        var cellRecords = new RenderProjectionRecord[1];
-        Assert.Equal(1, query.CopyCellStaticsTo(indoorCell, cellRecords));
-        Assert.Equal(indoorStatic.Id, cellRecords[0].Id);
-        Assert.Equal(1, query.CopyCellDynamicsTo(indoorCell, cellRecords));
-        Assert.Equal(cellDynamic.Id, cellRecords[0].Id);
         Assert.True(scene.Memory.EstimatedIndexBytes > 0);
     }
 
@@ -580,7 +573,6 @@ public sealed class ArchRenderSceneTests
         Assert.Equal(1, updated.IndexCounts.Translucent);
         Assert.Equal(1, updated.IndexCounts.LightCandidate);
         Assert.Equal(1, updated.IndexCounts.Dirty);
-        Assert.Equal(1, updated.GetCellDynamicCount(indoorCell));
 
         RenderProjectionRecord replacement = rebucketed with
         {
@@ -592,7 +584,6 @@ public sealed class ArchRenderSceneTests
         RenderSceneQuery replaced = scene.OpenQuery();
         Assert.Equal(0, replaced.IndexCounts.Dynamic);
         Assert.Equal(1, replaced.IndexCounts.IndoorCellStatic);
-        Assert.Equal(1, replaced.GetCellStaticCount(indoorCell));
 
         scene.Apply(
         [
@@ -1085,6 +1076,92 @@ public sealed class ArchRenderSceneTests
         Assert.Equal(changed.LatestRevision, query.DirectionalShadowTransformRevision);
     }
 
+    // Campaign OVERHAUL S2 review fix round (F5/F6): the LocalEntityId index.
+
+    private static RenderProjectionRecord WithLocalEntityId(
+        RenderProjectionRecord record,
+        uint localEntityId) =>
+        record with
+        {
+            Source = new RenderSourceMetadata(
+                LocalEntityId: localEntityId,
+                ServerGuid: 0,
+                SourceId: 1,
+                ParentCellId: record.Source.ParentCellId,
+                EffectCellId: 0,
+                BuildingShellAnchorCellId: 0,
+                TransformFingerprint: new RenderSceneHash128(1, 1),
+                GeometryFingerprint: new RenderSceneHash128(2, 2),
+                AppearanceFingerprint: new RenderSceneHash128(3, 3)),
+        };
+
+    [Fact]
+    public void TryGetByLocalEntityId_IgnoresEnvCellShellRecords()
+    {
+        // An EnvCell shell carries its CELL id in the entity-id slot; a
+        // dungeon cell id such as 0x8A020100 is numerically a procedural
+        // scenery entity id. The shell must never shadow the real entity.
+        const uint aliasedId = 0x8A020100u;
+        RenderSceneGeneration generation = Generation(31);
+        using var scene = new ArchRenderScene(generation);
+        RenderProjectionRecord shell = WithLocalEntityId(
+            Record(310, 1, RenderProjectionClass.IndoorCellStatic), aliasedId);
+        RenderProjectionRecord scenery = WithLocalEntityId(
+            Record(311, 1, RenderProjectionClass.OutdoorStatic), aliasedId);
+
+        scene.Apply(
+        [
+            RenderProjectionDelta.Register(generation, 1, shell),
+            RenderProjectionDelta.Register(generation, 2, scenery),
+        ]);
+        RenderSceneQuery query = scene.OpenQuery();
+
+        Assert.True(query.TryGetByLocalEntityId(aliasedId, out RenderProjectionRecord found));
+        Assert.Equal(scenery.Id, found.Id);
+
+        // Unregistering the shell never disturbs the entity's mapping.
+        scene.Apply(
+        [
+            RenderProjectionDelta.Unregister(
+                generation,
+                3,
+                shell.Id,
+                shell.OwnerIncarnation),
+        ]);
+        query = scene.OpenQuery();
+        Assert.True(query.TryGetByLocalEntityId(aliasedId, out found));
+        Assert.Equal(scenery.Id, found.Id);
+    }
+
+    [Fact]
+    public void Update_ThatRebindsTheLocalEntityId_MovesTheIndex()
+    {
+        RenderSceneGeneration generation = Generation(32);
+        using var scene = new ArchRenderScene(generation);
+        RenderProjectionRecord original = WithLocalEntityId(
+            Record(320, 1, RenderProjectionClass.LiveDynamicRoot), 19);
+        scene.Apply([RenderProjectionDelta.Register(generation, 1, original)]);
+        Assert.True(scene.OpenQuery().TryGetByLocalEntityId(19, out _));
+
+        // Same class, cell, flags, mesh count and sort key — only the id
+        // changes; the index must follow it (IndexMembershipEquals compares
+        // the id since the S2 review fix).
+        RenderProjectionRecord rebound = WithLocalEntityId(original, 20);
+        scene.Apply(
+        [
+            RenderProjectionDelta.Update(
+                RenderProjectionDeltaKind.UpdateFlags,
+                generation,
+                2,
+                rebound),
+        ]);
+        RenderSceneQuery query = scene.OpenQuery();
+
+        Assert.False(query.TryGetByLocalEntityId(19, out _));
+        Assert.True(query.TryGetByLocalEntityId(20, out RenderProjectionRecord found));
+        Assert.Equal(original.Id, found.Id);
+    }
+
     private static RenderProjectionRecord Record(
         ulong id,
         ulong incarnation,

tests/AcDream.App.Tests/Rendering/DirectionalShadowCasterFrameTests.cs

@@ -103,7 +103,6 @@ public sealed class DirectionalShadowCasterFrameTests
         Assert.Equal(
             [RenderSceneIndex.OutdoorStatic, RenderSceneIndex.OutdoorDynamic],
             source.CopiedIndices);
-        Assert.Equal(0, source.CellQueries);
         Assert.Equal(2, frame.Stats.IndexCopies);
     }
 
@@ -635,7 +634,6 @@ public sealed class DirectionalShadowCasterFrameTests
 
         public int IndexCountReads { get; private set; }
         public int IndexCopies { get; private set; }
-        public int CellQueries { get; private set; }
         public int ProjectionReads { get; private set; }
         public int BatchedProjectionCopies { get; private set; }
         public ulong TopologyRevision { get; private set; } = 1;
@@ -731,6 +729,32 @@ public sealed class DirectionalShadowCasterFrameTests
             return false;
         }
 
+        public bool TryGetByLocalEntityId(
+            RenderSceneGeneration generation,
+            uint localEntityId,
+            out RenderProjectionRecord record)
+        {
+            for (int index = 0; index < _statics.Length; index++)
+            {
+                if (_statics[index].Source.LocalEntityId == localEntityId)
+                {
+                    record = _statics[index];
+                    return true;
+                }
+            }
+            for (int index = 0; index < _dynamics.Length; index++)
+            {
+                if (_dynamics[index].Source.LocalEntityId == localEntityId)
+                {
+                    record = _dynamics[index];
+                    return true;
+                }
+            }
+
+            record = default;
+            return false;
+        }
+
         public int CopyById(
             RenderSceneGeneration generation,
             ReadOnlySpan<RenderProjectionId> ids,
@@ -791,25 +815,6 @@ public sealed class DirectionalShadowCasterFrameTests
             return values.Length;
         }
 
-        public int GetCellCount(
-            RenderSceneGeneration generation,
-            uint fullCellId,
-            bool dynamic)
-        {
-            CellQueries++;
-            throw new InvalidOperationException("Directional shadows do not query PView cells.");
-        }
-
-        public int CopyCellTo(
-            RenderSceneGeneration generation,
-            uint fullCellId,
-            bool dynamic,
-            Span<RenderProjectionRecord> destination)
-        {
-            CellQueries++;
-            throw new InvalidOperationException("Directional shadows do not query PView cells.");
-        }
-
 
         public void ReplaceStatics(
             RenderProjectionRecord[] values,

tests/AcDream.App.Tests/Rendering/Issue177StairDescentCameraFloodTests.cs

@@ -316,7 +316,7 @@ public class Issue177StairDescentCameraFloodTests
         Assert.Contains(
             worldData.GetCellStatics(FacilityHub | 0x015Eu).Records,
             record => record.Id == projectionId);
-        Assert.Equal(0, worldData.UnregisteredStaticRenderFallbackCount);
+        Assert.Equal(0, worldData.UnregisteredRenderMembershipCount);
     }
 
     /// <summary>

tests/AcDream.App.Tests/Rendering/Walk/WalkProductionWorldDataTests.cs

@@ -3,9 +3,23 @@ using AcDream.App.Rendering.Scene;
 using AcDream.App.Rendering.Scene.Arch;
 using AcDream.App.Rendering.Walk;
 using AcDream.Core.Physics;
+using AcDream.Core.World;
 
 namespace AcDream.App.Tests.Rendering.Walk;
 
+/// <summary>
+/// Campaign OVERHAUL S2 chunk 5: <see cref="WalkProductionWorldData"/> no
+/// longer sweeps the scene to rebuild membership into bucket dictionaries —
+/// <c>GetCellStatics</c>/<c>GetCellDynamics</c>/<c>GetOutdoorStatics</c>/
+/// <c>GetOutdoorDynamics</c> are borrowed, on-demand views over
+/// <see cref="ShadowObjectRegistry"/>'s retail per-cell part-entry product,
+/// resolved back to a <see cref="RenderProjectionRecord"/> through
+/// <see cref="RenderSceneQuery.TryGetByLocalEntityId"/>. Every test below
+/// drives the REAL production path end to end — a real (bare, no-DAT)
+/// <see cref="ShadowObjectRegistry"/> and a real <see cref="ArchRenderScene"/>
+/// — rather than a hand-fed bucket dictionary, since the resolution itself IS
+/// the thing under test now.
+/// </summary>
 public sealed class WalkProductionWorldDataTests
 {
     [Fact]
@@ -79,288 +93,6 @@ public sealed class WalkProductionWorldDataTests
             WalkProductionWorldData.BuildingShellBucketCellId(building));
     }
 
-    [Fact]
-    public void BucketOutdoorRecord_UsesEveryOutdoorPhysicsShadowCellAcrossLandblockEdge()
-    {
-        RenderProjectionRecord record = Record(
-            id: 0x1234u,
-            position: new Vector3(191f, 191f, 0f));
-        var buckets = new Dictionary<uint, List<RenderProjectionRecord>>();
-
-        WalkProductionWorldData.BucketOutdoorRecord(
-            in record,
-            [0xF07F0040u, 0xF0800001u, 0xF4180101u],
-            buckets,
-            renderCenterLbX: 0xF0,
-            renderCenterLbY: 0x7F);
-
-        Assert.Equal([0xF07F0040u, 0xF0800001u], buckets.Keys.Order());
-        Assert.All(buckets.Values, bucket => Assert.Equal(record, Assert.Single(bucket)));
-    }
-
-    [Fact]
-    public void BucketOutdoorRecord_UnregisteredEffectFallsBackToRootPositionCell()
-    {
-        RenderProjectionRecord record = Record(
-            id: 0x5678u,
-            position: new Vector3(193f, 25f, 0f));
-        var buckets = new Dictionary<uint, List<RenderProjectionRecord>>();
-
-        WalkProductionWorldData.BucketOutdoorRecord(
-            in record,
-            Array.Empty<uint>(),
-            buckets,
-            renderCenterLbX: 0xEF,
-            renderCenterLbY: 0x7F);
-
-        Assert.Equal([0xF07F0002u], buckets.Keys);
-        Assert.Equal(record, Assert.Single(buckets[0xF07F0002u]));
-    }
-
-    [Fact]
-    public void BucketIndoorRecord_InstallsCrossCellPartInBothInteriorCells()
-    {
-        RenderProjectionRecord record = Record(
-            id: 0x48A02035u,
-            position: new Vector3(55.25f, -46.47f, -3f)) with
-        {
-            Source = new RenderSourceMetadata() with
-            {
-                LocalEntityId = 0x48A02035u,
-                ParentCellId = 0x8A02015Fu,
-            },
-        };
-        var indoor = new Dictionary<uint, List<RenderProjectionRecord>>();
-        var outdoor = new Dictionary<uint, List<RenderProjectionRecord>>();
-
-        WalkProductionWorldData.BucketIndoorRecord(
-            in record,
-            [0x8A02015Fu, 0x8A02015Eu],
-            indoor,
-            outdoor);
-
-        Assert.Equal([0x8A02015Eu, 0x8A02015Fu], indoor.Keys.Order());
-        Assert.All(indoor.Values, bucket => Assert.Equal(record, Assert.Single(bucket)));
-        Assert.Empty(outdoor);
-    }
-
-    [Fact]
-    public void BucketIndoorRecord_CanCrossAnExitIntoLandscapeCell()
-    {
-        RenderProjectionRecord record = Record(
-            id: 0x48A02035u,
-            position: Vector3.Zero) with
-        {
-            Source = new RenderSourceMetadata() with
-            {
-                LocalEntityId = 0x48A02035u,
-                ParentCellId = 0x8A02015Fu,
-            },
-        };
-        var indoor = new Dictionary<uint, List<RenderProjectionRecord>>();
-        var outdoor = new Dictionary<uint, List<RenderProjectionRecord>>();
-
-        WalkProductionWorldData.BucketIndoorRecord(
-            in record,
-            [0x8A02015Fu, 0x8A020021u],
-            indoor,
-            outdoor);
-
-        Assert.Equal(record, Assert.Single(indoor[0x8A02015Fu]));
-        Assert.Equal(record, Assert.Single(outdoor[0x8A020021u]));
-    }
-
-    [Fact]
-    public void BucketDynamicRecord_InstallsMultipartPlayerInEveryCrossedInteriorCell()
-    {
-        RenderProjectionRecord record = Record(
-            id: 0x000F4243u,
-            position: new Vector3(58.81f, -49.42f, -0.85f)) with
-        {
-            Source = new RenderSourceMetadata() with
-            {
-                LocalEntityId = 0x000F4243u,
-                ParentCellId = 0x8A02015Eu,
-            },
-        };
-        var indoor = new Dictionary<uint, List<RenderProjectionRecord>>();
-        var outdoor = new Dictionary<uint, List<RenderProjectionRecord>>();
-
-        WalkProductionWorldData.BucketDynamicRecord(
-            in record,
-            [0x8A02015Eu, 0x8A02015Fu, 0x8A0201C1u],
-            indoor,
-            outdoor,
-            renderCenterLbX: 0x8A,
-            renderCenterLbY: 0x02);
-
-        Assert.Equal(
-            [0x8A02015Eu, 0x8A02015Fu, 0x8A0201C1u],
-            indoor.Keys.Order());
-        Assert.All(
-            indoor.Values,
-            bucket => Assert.Equal(record, Assert.Single(bucket)));
-        Assert.Empty(outdoor);
-    }
-
-    [Fact]
-    public void BucketDynamicRecord_UnregisteredInteriorEffectFallsBackToParentCell()
-    {
-        RenderProjectionRecord record = Record(
-            id: 0x00001234u,
-            position: Vector3.Zero) with
-        {
-            Source = new RenderSourceMetadata() with
-            {
-                LocalEntityId = 0x00001234u,
-                ParentCellId = 0x8A02015Fu,
-            },
-        };
-        var indoor = new Dictionary<uint, List<RenderProjectionRecord>>();
-        var outdoor = new Dictionary<uint, List<RenderProjectionRecord>>();
-
-        WalkProductionWorldData.BucketDynamicRecord(
-            in record,
-            Array.Empty<uint>(),
-            indoor,
-            outdoor,
-            renderCenterLbX: 0x8A,
-            renderCenterLbY: 0x02);
-
-        Assert.Equal(record, Assert.Single(indoor[0x8A02015Fu]));
-        Assert.Empty(outdoor);
-    }
-
-    // Campaign OVERHAUL S2 chunk 4: ResolveDynamicRenderCells is now a direct
-    // TryGetRetailCellArray read for EVERY dynamic record, children included
-    // — ShadowObjectRegistry.AttachChild owns Contract B's child-inheritance
-    // recursion at the registry, so the render-side parent-chain walk this
-    // test used to exercise no longer exists.
-
-    private static ShadowShape ChildBsp(uint gfxObjId) =>
-        ShadowShape.Bsp(
-            gfxObjId,
-            Vector3.Zero,
-            Quaternion.Identity,
-            scale: 1f,
-            localGeometry: ShadowPartGeometry.Create(
-                new FlatCollisionSphere(Vector3.Zero, 1f), null));
-
-    [Fact]
-    public void ResolveDynamicRenderCells_AttachedChildReadsTheRegistrysRetailCellArrayDirectly()
-    {
-        var shadows = new ShadowObjectRegistry();
-        const uint rootId = 0x5000000Au;
-        const uint childId = 0x800045EEu;
-        IReadOnlyList<ShadowShape> rootParts = new[] { ChildBsp(0x02000001u) };
-
-        shadows.RegisterMultiPart(
-            rootId,
-            new Vector3(12f, 12f, 50f),
-            Quaternion.Identity,
-            rootParts,
-            state: 0u,
-            flags: EntityCollisionFlags.None,
-            worldOffsetX: 0f,
-            worldOffsetY: 0f,
-            landblockId: 0xF4180000u,
-            seedCellId: 0xF4180104u,
-            isStatic: false,
-            partArray: rootParts);
-        Assert.True(shadows.TryGetRetailCellArray(rootId, out IReadOnlyList<uint> rootCells));
-        Assert.NotEmpty(rootCells); // the fixture must actually exercise a flood
-
-        // No render-side parent walk any more: Contract B's inheritance is
-        // owned by the registry at attach time.
-        Assert.True(shadows.AttachChild(childId, rootId, new[] { ChildBsp(0x02000002u) }));
-
-        RenderProjectionRecord wand = Record(
-            id: childId,
-            position: Vector3.Zero) with
-        {
-            Source = new RenderSourceMetadata() with
-            {
-                LocalEntityId = childId,
-                ParentCellId = 0xF4180104u,
-            },
-            EntityPayload = new RenderEntityPayload() with
-            {
-                CasterIdentity = RenderCasterIdentityKind.EquippedChild,
-            },
-        };
-
-        IReadOnlyList<uint> cells =
-            WalkProductionWorldData.ResolveDynamicRenderCells(
-                in wand,
-                id => shadows.TryGetRetailCellArray(id, out IReadOnlyList<uint> c)
-                    ? (true, c)
-                    : (false, Array.Empty<uint>()),
-                shadows.GetOwnerCells,
-                out bool usedFallback);
-
-        Assert.False(usedFallback);
-        Assert.Equal(rootCells, cells);
-    }
-
-    [Fact]
-    public void ResolveDynamicRenderCells_UnregisteredEntityFallsBackToOwnerCells()
-    {
-        var shadows = new ShadowObjectRegistry();
-        const uint entityId = 0x00099Fu;
-        IReadOnlyList<ShadowShape> shapes = new[] { ChildBsp(0x02000003u) };
-        shadows.RegisterMultiPart(
-            entityId,
-            new Vector3(12f, 12f, 50f),
-            Quaternion.Identity,
-            shapes,
-            state: 0u,
-            flags: EntityCollisionFlags.None,
-            worldOffsetX: 0f,
-            worldOffsetY: 0f,
-            landblockId: 0xF4180000u,
-            seedCellId: 0xF4180104u,
-            isStatic: false);
-        // No partArray supplied above -> no retail cell array registered for
-        // this entity (item E of the S2 chunk-1 contract), so the ordinary
-        // collision-flood answer is the conservative fallback.
-        Assert.False(shadows.TryGetRetailCellArray(entityId, out _));
-        Assert.NotEmpty(shadows.GetOwnerCells(entityId));
-
-        RenderProjectionRecord record = Record(
-            id: entityId,
-            position: Vector3.Zero) with
-        {
-            Source = new RenderSourceMetadata() with
-            {
-                LocalEntityId = entityId,
-                ParentCellId = 0xF4180104u,
-            },
-        };
-
-        IReadOnlyList<uint> cells =
-            WalkProductionWorldData.ResolveDynamicRenderCells(
-                in record,
-                id => shadows.TryGetRetailCellArray(id, out IReadOnlyList<uint> c)
-                    ? (true, c)
-                    : (false, Array.Empty<uint>()),
-                shadows.GetOwnerCells,
-                out bool usedFallback);
-
-        Assert.True(usedFallback);
-        Assert.Equal(shadows.GetOwnerCells(entityId), cells);
-    }
-
-    // -----------------------------------------------------------------
-    // Campaign OVERHAUL S2 chunk 2: BeginFrame's indoor static sweep now
-    // borrows membership from ShadowObjectRegistry.TryGetRetailCellArray
-    // instead of rebuilding it (the deleted ResolveStaticRenderCells /
-    // ShadowObjectRegistry.ComputeStaticRenderCells pair). These two tests
-    // drive the REAL production path end to end — a real (bare, no-DAT)
-    // ShadowObjectRegistry, a real ArchRenderScene, and BeginFrame itself —
-    // rather than the hardcoded-cell-array style of the Bucket* tests above,
-    // which exercise only the (unchanged) bucketing primitive.
-    // -----------------------------------------------------------------
-
     private static ShadowShape Bsp(uint gfxObjId, float radius = 1f) =>
         ShadowShape.Bsp(
             gfxObjId,
@@ -388,20 +120,54 @@ public sealed class WalkProductionWorldDataTests
                 SourceId = sourceId,
                 ParentCellId = parentCellId,
             },
+            // Every production entity record carries its MeshRefs
+            // (RenderProjectionRecordFactory); only an EnvCell SHELL has no
+            // payload, and ArchRenderScene keeps shells out of the
+            // LocalEntityId index on exactly that distinction.
+            EntityPayload = new RenderEntityPayload() with
+            {
+                MeshRefs = [new MeshRef(sourceId, Matrix4x4.Identity)],
+            },
         };
 
-    [Fact]
-    public void BeginFrame_IndoorStatic_RegisteredEntityUsesRegistryRetailCellArray()
-    {
-        const uint entityId = 0x48A02001u;
-        const uint retailCellId = 0x8A02015Fu;
-        // A DECOY parent cell, deliberately different from the registered
-        // retail array's cell, so the assertions below can only pass if the
-        // indoor sweep actually consulted the registry rather than falling
-        // back to the authored parent.
-        const uint decoyParentCellId = 0x8A0201C1u;
+    private static RenderProjectionRecord DynamicRecord(
+        uint entityId, uint sourceId, uint parentCellId) =>
+        IndoorStaticRecord(entityId, sourceId, parentCellId) with
+        {
+            Id = RenderProjectionId.FromRaw(0x0100_0000_0000_0000u | entityId),
+            ProjectionClass = RenderProjectionClass.LiveDynamicRoot,
+        };
 
-        var shadows = new ShadowObjectRegistry();
+    private static RenderProjectionRecord OutdoorStaticRecord(
+        uint entityId, uint sourceId, uint cellId, bool isBuildingShell = false) =>
+        new RenderProjectionRecord() with
+        {
+            Id = RenderProjectionId.FromRaw(0x0200_0000_0000_0000u | entityId),
+            ProjectionClass = RenderProjectionClass.OutdoorStatic,
+            OwnerIncarnation = RenderOwnerIncarnation.FromRaw(1),
+            Transform = new RenderTransform(Matrix4x4.Identity),
+            PreviousTransform = new PreviousRenderTransform(Matrix4x4.Identity),
+            Residency = new RenderSpatialResidency(
+                RenderSpatialBucket.FromRaw(cellId), cellId & 0xFFFF0000u, cellId),
+            Flags = RenderProjectionFlags.Draw,
+            Source = new RenderSourceMetadata() with
+            {
+                LocalEntityId = entityId,
+                SourceId = sourceId,
+                ParentCellId = cellId,
+            },
+            EntityPayload = new RenderEntityPayload() with
+            {
+                IsBuildingShell = isBuildingShell,
+            },
+        };
+
+    private static void Register(
+        ShadowObjectRegistry shadows,
+        uint entityId,
+        uint seedCellId,
+        uint landblockId)
+    {
         IReadOnlyList<ShadowShape> parts = new[] { Bsp(0x01001234u) };
         shadows.RegisterMultiPart(
             entityId,
@@ -412,10 +178,26 @@ public sealed class WalkProductionWorldDataTests
             flags: EntityCollisionFlags.None,
             worldOffsetX: 0f,
             worldOffsetY: 0f,
-            landblockId: 0x8A020000u,
-            seedCellId: retailCellId,
+            landblockId: landblockId,
+            seedCellId: seedCellId,
             isStatic: true,
             partArray: parts);
+    }
+
+    [Fact]
+    public void GetCellStatics_RegisteredEntityIsResolvedByLocalEntityIdAtTheRetailCell()
+    {
+        const uint entityId = 0x48A02001u;
+        const uint retailCellId = 0x8A02015Fu;
+        // A DECOY parent cell, deliberately different from the registered
+        // retail array's cell, so the assertions below can only pass if the
+        // per-cell view actually consulted the registry rather than the
+        // authored parent (deleted alongside the sweep this test used to
+        // exercise).
+        const uint decoyParentCellId = 0x8A0201C1u;
+
+        var shadows = new ShadowObjectRegistry();
+        Register(shadows, entityId, retailCellId, landblockId: 0x8A020000u);
         Assert.True(shadows.TryGetRetailCellArray(entityId, out IReadOnlyList<uint> retailCells));
         Assert.Equal(new[] { retailCellId }, retailCells);
 
@@ -435,34 +217,265 @@ public sealed class WalkProductionWorldDataTests
         Assert.DoesNotContain(
             worldData.GetCellStatics(decoyParentCellId).Records,
             record => record.Id == projection.Id);
-        Assert.Equal(0, worldData.UnregisteredStaticRenderFallbackCount);
+        Assert.Equal(0, worldData.UnregisteredRenderMembershipCount);
     }
 
     [Fact]
-    public void BeginFrame_IndoorStatic_UnregisteredEntityFallsBackToParentCellAndCountsFallback()
+    public void GetCellStatics_RegistryAheadOfSceneContributesToNoCellAndCountsFallback()
     {
         const uint entityId = 0x48A02002u;
+        const uint retailCellId = 0x8A02015Fu;
+
+        // The registry HAS flooded this entity into its retail CELLARRAY —
+        // exactly the streaming-window race chunk 5 keeps as the ONE
+        // remaining fallback: the physics publisher (registry) ran before
+        // the presentation journal applied this frame's projected record.
+        var shadows = new ShadowObjectRegistry();
+        Register(shadows, entityId, retailCellId, landblockId: 0x8A020000u);
+        Assert.True(shadows.TryGetRetailCellArray(entityId, out _));
+
+        RenderSceneGeneration generation = RenderSceneGeneration.FromRaw(1);
+        using var scene = new ArchRenderScene(generation);
+        // Deliberately no scene.Apply — the projected record does not exist
+        // yet this frame.
+
+        var worldData = new WalkProductionWorldData(new WalkBuildingRegistry(), shadows);
+        worldData.BeginFrame(
+            scene.OpenQuery(), 0x8A020000u, renderCenterLbX: 0x8A, renderCenterLbY: 0x02);
+
+        Assert.Equal(0, worldData.GetCellStatics(retailCellId).Records.Count);
+        Assert.Equal(1, worldData.UnregisteredRenderMembershipCount);
+    }
+
+    [Fact]
+    public void GetCellStatics_UnregisteredEntityContributesToNoCellWithoutCounting()
+    {
+        // The OPPOSITE race: the scene has a projected record, but the
+        // registry never registered a retail CELLARRAY for this entity at
+        // all. Under the borrowed-view model this entity is never visited
+        // (nothing in the registry names it), so it correctly appears in NO
+        // cell and does not inflate the one remaining fallback counter —
+        // that counter only tracks entities the REGISTRY has flooded.
+        const uint entityId = 0x48A02003u;
         const uint parentCellId = 0x8A02015Fu;
 
-        // Bare, empty registry: entityId is never registered, so
-        // TryGetRetailCellArray must answer false for it.
         var shadows = new ShadowObjectRegistry();
         Assert.False(shadows.TryGetRetailCellArray(entityId, out _));
 
         RenderSceneGeneration generation = RenderSceneGeneration.FromRaw(1);
         using var scene = new ArchRenderScene(generation);
         RenderProjectionRecord projection =
-            IndoorStaticRecord(entityId, sourceId: 0x02000002u, parentCellId);
+            IndoorStaticRecord(entityId, sourceId: 0x02000003u, parentCellId);
         scene.Apply([RenderProjectionDelta.Register(generation, 1, projection)]);
 
+        var worldData = new WalkProductionWorldData(new WalkBuildingRegistry(), shadows);
+        worldData.BeginFrame(
+            scene.OpenQuery(), 0x8A020000u, renderCenterLbX: 0x8A, renderCenterLbY: 0x02);
+
+        Assert.Equal(0, worldData.GetCellStatics(parentCellId).Records.Count);
+        Assert.Equal(0, worldData.UnregisteredRenderMembershipCount);
+    }
+
+    [Fact]
+    public void UnregisteredRenderMembershipCount_CountsDistinctEntitiesNotCellVisits()
+    {
+        // One entity crossing SEVERAL cells — outdoor, since the bbox flood's
+        // fixed outdoor expansion reliably crosses cells even against a bare
+        // registry with no portal DAT data to cross INDOOR cells with (see
+        // GetOutdoorStatics_UsesTheSameRegistryDrivenViewAsIndoor) — all
+        // unresolved in the scene, must count once total, not once per cell
+        // the registry flooded it into.
+        const uint entityId = 0x87640002u;
+        const uint seedCellId = 0x87640030u;
+
+        IReadOnlyList<ShadowShape> parts = new[] { Bsp(0x01001234u) };
+        var shadows = new ShadowObjectRegistry();
+        shadows.RegisterMultiPart(
+            entityId,
+            Vector3.Zero,
+            Quaternion.Identity,
+            parts,
+            state: 0u,
+            flags: EntityCollisionFlags.None,
+            worldOffsetX: 0f,
+            worldOffsetY: 0f,
+            landblockId: 0x87640000u,
+            seedCellId: seedCellId,
+            isStatic: true,
+            partArray: parts);
+        Assert.True(shadows.TryGetRetailCellArray(entityId, out IReadOnlyList<uint> cells));
+        Assert.True(cells.Count >= 2, "fixture must actually cross more than one cell");
+
+        RenderSceneGeneration generation = RenderSceneGeneration.FromRaw(1);
+        using var scene = new ArchRenderScene(generation);
+
+        var worldData = new WalkProductionWorldData(new WalkBuildingRegistry(), shadows);
+        worldData.BeginFrame(
+            scene.OpenQuery(), 0x87640000u, renderCenterLbX: 0x87, renderCenterLbY: 0x64);
+
+        foreach (uint cellId in cells)
+            Assert.Equal(0, worldData.GetOutdoorStatics(cellId).Records.Count);
+
+        Assert.Equal(1, worldData.UnregisteredRenderMembershipCount);
+    }
+
+    [Fact]
+    public void GetCellDynamics_OnlyReturnsDynamicClassRecordsFromTheSameCell()
+    {
+        const uint staticEntityId = 0x48A02010u;
+        const uint dynamicEntityId = 0x48A02011u;
+        const uint sharedCellId = 0x8A02015Fu;
+
+        var shadows = new ShadowObjectRegistry();
+        Register(shadows, staticEntityId, sharedCellId, landblockId: 0x8A020000u);
+        Register(shadows, dynamicEntityId, sharedCellId, landblockId: 0x8A020000u);
+
+        RenderSceneGeneration generation = RenderSceneGeneration.FromRaw(1);
+        using var scene = new ArchRenderScene(generation);
+        RenderProjectionRecord staticProjection =
+            IndoorStaticRecord(staticEntityId, sourceId: 0x02000010u, sharedCellId);
+        RenderProjectionRecord dynamicProjection =
+            DynamicRecord(dynamicEntityId, sourceId: 0x02000011u, sharedCellId);
+        scene.Apply([
+            RenderProjectionDelta.Register(generation, 1, staticProjection),
+            RenderProjectionDelta.Register(generation, 2, dynamicProjection),
+        ]);
+
         var worldData = new WalkProductionWorldData(new WalkBuildingRegistry(), shadows);
         worldData.BeginFrame(
             scene.OpenQuery(), 0x8A020000u, renderCenterLbX: 0x8A, renderCenterLbY: 0x02);
 
         Assert.Contains(
-            worldData.GetCellStatics(parentCellId).Records,
+            worldData.GetCellStatics(sharedCellId).Records,
+            record => record.Id == staticProjection.Id);
+        Assert.DoesNotContain(
+            worldData.GetCellStatics(sharedCellId).Records,
+            record => record.Id == dynamicProjection.Id);
+
+        Assert.Contains(
+            worldData.GetCellDynamics(sharedCellId).Records,
+            record => record.Id == dynamicProjection.Id);
+        Assert.DoesNotContain(
+            worldData.GetCellDynamics(sharedCellId).Records,
+            record => record.Id == staticProjection.Id);
+    }
+
+    [Fact]
+    public void GetCellStatics_ExcludesBuildingShellRecordsFromTheSameCell()
+    {
+        const uint shellEntityId = 0x48A02020u;
+        const uint ordinaryEntityId = 0x48A02021u;
+        const uint sharedCellId = 0x8A02015Fu;
+
+        var shadows = new ShadowObjectRegistry();
+        Register(shadows, shellEntityId, sharedCellId, landblockId: 0x8A020000u);
+        Register(shadows, ordinaryEntityId, sharedCellId, landblockId: 0x8A020000u);
+
+        RenderSceneGeneration generation = RenderSceneGeneration.FromRaw(1);
+        using var scene = new ArchRenderScene(generation);
+        RenderProjectionRecord shellProjection =
+            IndoorStaticRecord(shellEntityId, sourceId: 0x02000020u, sharedCellId) with
+            {
+                EntityPayload = new RenderEntityPayload() with { IsBuildingShell = true },
+            };
+        RenderProjectionRecord ordinaryProjection =
+            IndoorStaticRecord(ordinaryEntityId, sourceId: 0x02000021u, sharedCellId);
+        scene.Apply([
+            RenderProjectionDelta.Register(generation, 1, shellProjection),
+            RenderProjectionDelta.Register(generation, 2, ordinaryProjection),
+        ]);
+
+        var worldData = new WalkProductionWorldData(new WalkBuildingRegistry(), shadows);
+        worldData.BeginFrame(
+            scene.OpenQuery(), 0x8A020000u, renderCenterLbX: 0x8A, renderCenterLbY: 0x02);
+
+        Assert.DoesNotContain(
+            worldData.GetCellStatics(sharedCellId).Records,
+            record => record.Id == shellProjection.Id);
+        Assert.Contains(
+            worldData.GetCellStatics(sharedCellId).Records,
+            record => record.Id == ordinaryProjection.Id);
+    }
+
+    [Fact]
+    public void GetOutdoorStatics_UsesTheSameRegistryDrivenViewAsIndoor()
+    {
+        const uint entityId = 0x87640001u;
+        const uint outdoorCellId = 0x87640030u;
+
+        var shadows = new ShadowObjectRegistry();
+        Register(shadows, entityId, outdoorCellId, landblockId: 0x87640000u);
+        Assert.True(shadows.TryGetRetailCellArray(entityId, out IReadOnlyList<uint> retailCells));
+        // The outdoor bbox flood's fixed expansion crosses more than the
+        // seed cell even for a small radius; only the seed cell's own
+        // membership matters for this test.
+        Assert.Contains(outdoorCellId, retailCells);
+
+        RenderSceneGeneration generation = RenderSceneGeneration.FromRaw(1);
+        using var scene = new ArchRenderScene(generation);
+        RenderProjectionRecord projection =
+            OutdoorStaticRecord(entityId, sourceId: 0x02000030u, outdoorCellId);
+        scene.Apply([RenderProjectionDelta.Register(generation, 1, projection)]);
+
+        var worldData = new WalkProductionWorldData(new WalkBuildingRegistry(), shadows);
+        worldData.BeginFrame(
+            scene.OpenQuery(), 0x87640000u, renderCenterLbX: 0x87, renderCenterLbY: 0x64);
+
+        Assert.Contains(
+            worldData.GetOutdoorStatics(outdoorCellId).Records,
             record => record.Id == projection.Id);
-        Assert.Equal(1, worldData.UnregisteredStaticRenderFallbackCount);
+    }
+
+    [Fact]
+    public void GetCellStatics_CachesTheResultForTheRestOfTheFrame()
+    {
+        const uint entityId = 0x48A02030u;
+        const uint retailCellId = 0x8A02015Fu;
+
+        var shadows = new ShadowObjectRegistry();
+        Register(shadows, entityId, retailCellId, landblockId: 0x8A020000u);
+
+        RenderSceneGeneration generation = RenderSceneGeneration.FromRaw(1);
+        using var scene = new ArchRenderScene(generation);
+        RenderProjectionRecord projection =
+            IndoorStaticRecord(entityId, sourceId: 0x02000030u, retailCellId);
+        scene.Apply([RenderProjectionDelta.Register(generation, 1, projection)]);
+
+        var worldData = new WalkProductionWorldData(new WalkBuildingRegistry(), shadows);
+        worldData.BeginFrame(
+            scene.OpenQuery(), 0x8A020000u, renderCenterLbX: 0x8A, renderCenterLbY: 0x02);
+
+        WalkFrameStaticRecords first = worldData.GetCellStatics(retailCellId);
+        WalkFrameStaticRecords second = worldData.GetCellStatics(retailCellId);
+
+        Assert.Equal(first.Records.Array, second.Records.Array);
+        Assert.Equal(first.Records.Offset, second.Records.Offset);
+        Assert.Equal(first.Records.Count, second.Records.Count);
+    }
+
+    [Fact]
+    public void StaticBucketContains_FindsARegisteredSourceIdInItsRetailCell()
+    {
+        const uint entityId = 0x48A02040u;
+        const uint sourceId = 0x020009A2u;
+        const uint retailCellId = 0xF4180112u;
+
+        var shadows = new ShadowObjectRegistry();
+        Register(shadows, entityId, retailCellId, landblockId: 0xF4180000u);
+
+        RenderSceneGeneration generation = RenderSceneGeneration.FromRaw(1);
+        using var scene = new ArchRenderScene(generation);
+        RenderProjectionRecord projection =
+            IndoorStaticRecord(entityId, sourceId, retailCellId);
+        scene.Apply([RenderProjectionDelta.Register(generation, 1, projection)]);
+
+        var worldData = new WalkProductionWorldData(new WalkBuildingRegistry(), shadows);
+        worldData.BeginFrame(
+            scene.OpenQuery(), 0xF4180000u, renderCenterLbX: 0xF4, renderCenterLbY: 0x18);
+
+        Assert.True(worldData.StaticBucketContains(retailCellId, sourceId));
+        Assert.False(worldData.StaticBucketContains(retailCellId, sourceId + 1));
+        Assert.False(worldData.StaticBucketContains(0xF4180107u, sourceId));
     }
 
     private static RenderProjectionRecord Record(uint id, Vector3 position) =>

tests/AcDream.App.Tests/Streaming/LandblockPhysicsPublisherTests.cs

@@ -1333,6 +1333,73 @@ public sealed class LandblockPhysicsPublisherTests
         Resolved = new Dictionary<ushort, ResolvedPolygon>(),
     };
 
+    /// <summary>
+    /// Campaign OVERHAUL S2 chunk 5 closeout (G2 self-gate finding): a DAT
+    /// static with visual parts but no collision geometry is still flooded
+    /// into its cells by retail (calc_cross_cells_static 0x00515160 bbox route
+    /// + add_shadows_to_cells 0x00514ae0 AddPartsShadow rows), so the static
+    /// publisher registers it render-only — retail cell array + part entries,
+    /// zero collision rows. Before this pin the publisher skipped it outright
+    /// and, with the walk's parent-cell fallback deleted, the Facility Hub's
+    /// decorative wall panels vanished.
+    /// </summary>
+    [Fact]
+    public void CompletePublication_NonCollidingStaticRegistersRenderOnly()
+    {
+        const uint gfxObjId = 0x01000079u;
+        var fixture = Fixture();
+        fixture.Cache.RegisterGfxObjForTest(gfxObjId, RenderOnlyGfx(radius: 0.8f));
+        WorldEntity entity = new()
+        {
+            Id = 0x80A9B402u,
+            SourceGfxObjOrSetupId = gfxObjId,
+            Position = new Vector3(12f, 12f, 0f),
+            Rotation = Quaternion.Identity,
+            MeshRefs = [new MeshRef(gfxObjId, Matrix4x4.Identity)],
+        };
+
+        Publish(fixture.Publisher, Build(FirstLandblock, [entity]));
+
+        ShadowObjectRegistry shadows = fixture.Engine.ShadowObjects;
+        // No collision row anywhere (Contract B: nothing to contribute).
+        Assert.Empty(shadows.AllEntriesForDebug());
+        // But the retail render product exists: cell array + one part entry.
+        Assert.True(shadows.TryGetRetailCellArray(entity.Id, out var cells));
+        Assert.NotEmpty(cells);
+        Assert.Equal(RetailCellArrayRoute.BoundingBox, shadows.GetRetailCellArrayRoute(entity.Id));
+        int matching = 0;
+        foreach (RetailPartEntry part in shadows.GetRetailPartEntriesInCell(cells[0]))
+        {
+            if (part.EntityId != entity.Id)
+                continue;
+            matching++;
+            Assert.Equal(gfxObjId, part.GfxObjId);
+        }
+        Assert.Equal(1, matching);
+        Assert.Equal(0, fixture.Publisher.Diagnostics.StaticBspOwnerCount);
+        Assert.Equal(0, fixture.Publisher.Diagnostics.StaticCylinderOwnerCount);
+    }
+
+    /// <summary>A GfxObj with visual bounds and NO physics BSP — a purely
+    /// decorative static part.</summary>
+    private static GfxObjPhysics RenderOnlyGfx(float radius) => new()
+    {
+        BoundingSphere = new Sphere
+        {
+            Origin = Vector3.Zero,
+            Radius = radius,
+        },
+        PhysicsPolygons = new Dictionary<ushort, Polygon>(),
+        Vertices = new VertexArray(),
+        Resolved = new Dictionary<ushort, ResolvedPolygon>(),
+        VisualBounds = new FlatGfxObjVisualBounds(
+            new Vector3(-radius),
+            new Vector3(radius),
+            Vector3.Zero,
+            radius,
+            new Vector3(radius)),
+    };
+
     private static GfxObj PhysicsGfx() => new()
     {
         Flags = DatReaderWriter.Enums.GfxObjFlags.HasPhysics,

tests/AcDream.Content.Tests/LandblockPhysicsContentBuilderStaticSphereTests.cs

@@ -108,4 +108,77 @@ public sealed class LandblockPhysicsContentBuilderStaticSphereTests
             Assert.Equal(expectedOrdered[i].CylHeight, entries[i].CylHeight);
         }
     }
+
+    /// <summary>
+    /// Campaign OVERHAUL S2 chunk 5 closeout (G2 self-gate finding): a DAT
+    /// static whose GfxObj has visual geometry but no physics BSP is still a
+    /// CPhysicsObj retail floods into its cells (calc_cross_cells_static
+    /// 0x00515160 bbox route over the part array + add_shadows_to_cells
+    /// 0x00514ae0 AddPartsShadow rows), so the Content publisher registers it
+    /// render-only: retail cell array + part entry, zero collision rows, and
+    /// it still counts as a no-collision owner.
+    /// </summary>
+    [Fact]
+    public void PublishStaticCollision_NonCollidingGfxObjStatic_RegistersRenderOnly()
+    {
+        const uint gfxObjId = 0x01000043u;
+        var gfx = new GfxObj
+        {
+            VertexArray = new VertexArray
+            {
+                Vertices = new Dictionary<ushort, SWVertex>
+                {
+                    [0] = new SWVertex { Origin = new Vector3(-0.5f, -0.5f, 0f) },
+                    [1] = new SWVertex { Origin = new Vector3(0.5f, -0.5f, 0f) },
+                    [2] = new SWVertex { Origin = new Vector3(0f, 0.5f, 1.2f) },
+                },
+            },
+        };
+        FlatGfxObjCollisionAsset asset = FlatCollisionAssetBuilder.FlattenGfxObj(gfx);
+        Assert.True(asset.PhysicsBsp.RootIndex < 0); // the fixture really has no physics
+        Assert.NotNull(asset.VisualBounds);
+
+        var entity = new WorldEntity
+        {
+            Id = 0x80A9B402u,
+            SourceGfxObjOrSetupId = gfxObjId,
+            Position = new Vector3(12f, 12f, 0f),
+            Rotation = Quaternion.Identity,
+            MeshRefs = new[] { new MeshRef(gfxObjId, Matrix4x4.Identity) },
+        };
+        var landblock = new LoadedLandblock(
+            LandblockId,
+            new LandBlock { Terrain = new TerrainInfo[81], Height = new byte[81] },
+            new[] { entity });
+        var collisions = new LandblockCollisionBuild(
+            ImmutableDictionary<uint, FlatGfxObjCollisionAsset>.Empty.Add(gfxObjId, asset),
+            ImmutableDictionary<uint, FlatSetupCollision>.Empty,
+            ImmutableDictionary<uint, FlatCellStructureCollisionAsset>.Empty,
+            ImmutableDictionary<uint, FlatEnvCellTopology>.Empty,
+            ImmutableArray.Create(gfxObjId),
+            ImmutableArray<uint>.Empty,
+            ImmutableArray<uint>.Empty);
+        var engine = new PhysicsEngine();
+        var cache = new PhysicsDataCache();
+        LandblockPhysicsContentBuilder.CachePreparedObjects(cache, collisions);
+
+        LandblockPhysicsContentBuilder.StaticCollisionPublication publication =
+            LandblockPhysicsContentBuilder.PublishStaticCollision(
+                engine, cache, landblock, collisions, origin: Vector3.Zero);
+
+        Assert.Equal(0, publication.SetupOwnerCount);
+        Assert.Equal(0, publication.BspOwnerCount);
+        Assert.Equal(1, publication.NoCollisionCount);
+        Assert.Empty(engine.ShadowObjects.AllEntriesForDebug());
+        Assert.True(engine.ShadowObjects.TryGetRetailCellArray(entity.Id, out var cells));
+        Assert.NotEmpty(cells);
+        Assert.Equal(
+            RetailCellArrayRoute.BoundingBox,
+            engine.ShadowObjects.GetRetailCellArrayRoute(entity.Id));
+        var parts = engine.ShadowObjects.GetRetailPartEntriesInCell(cells[0])
+            .Where(part => part.EntityId == entity.Id)
+            .ToArray();
+        Assert.Single(parts);
+        Assert.Equal(gfxObjId, parts[0].GfxObjId);
+    }
 }

tests/AcDream.Core.Tests/Physics/ShadowObjectRegistryRetailCellArrayTests.cs

@@ -867,4 +867,388 @@ public class ShadowObjectRegistryRetailCellArrayTests
         Assert.True(reg.TryGetRetailCellArray(childId, out var childCells));
         Assert.Equal(rootCellsAfter, childCells);
     }
+
+    // -------------------------------------------------------------------
+    // Campaign OVERHAUL S2 chunk 5 (item B): a live entity whose collision
+    // dispatch produced NO shapes but whose Setup still has a visual part
+    // array (the retail short-lived spell/visual effect-object case) still
+    // registers for render — Contract A's cylsphere-vs-bbox TEST reads the
+    // COLLISION shapes (none here, so it is always false) and the flood
+    // unconditionally falls through to the bbox route over the WHOLE part
+    // array. No ShadowEntry collision row is ever published; only the
+    // retail CELLARRAY and per-cell RetailPartEntry rows are.
+    // -------------------------------------------------------------------
+
+    [Fact]
+    public void RegisterMultiPart_EmptyShapesWithPartArray_RegistersRenderOnlyNoCollisionRows()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint entityId = 0x50u;
+        IReadOnlyList<ShadowShape> partArray = new[] { Bsp(0x0100_0060u, radius: 2f) };
+
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, Array.Empty<ShadowShape>(),
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: true, partArray: partArray);
+
+        Assert.True(reg.TryGetRetailCellArray(entityId, out var cells));
+        Assert.Equal(new[] { CellA }, cells);
+        Assert.Equal(RetailCellArrayRoute.BoundingBox, reg.GetRetailCellArrayRoute(entityId));
+
+        var entries = reg.GetRetailPartEntriesInCell(CellA)
+            .Where(e => e.EntityId == entityId).ToList();
+        Assert.Single(entries);
+        Assert.Equal(0x0100_0060u, entries[0].GfxObjId);
+
+        // No collision row anywhere: shadow_object_list gets nothing for an
+        // object with no part to contribute to it (Contract B).
+        Assert.Empty(reg.GetOwnerCells(entityId));
+    }
+
+    [Fact]
+    public void RegisterMultiPart_EmptyShapesAndNoPartArray_StillDeregisters()
+    {
+        // Byte-for-byte prior behavior: a caller that supplies neither
+        // collision shapes nor a part array is a genuine deregistration, not
+        // a render-only registration.
+        var reg = new ShadowObjectRegistry();
+        const uint entityId = 0x51u;
+        IReadOnlyList<ShadowShape> parts = new[] { Bsp(0x0100_0061u) };
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, parts,
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: true, partArray: parts);
+        Assert.True(reg.TryGetRetailCellArray(entityId, out _));
+
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, Array.Empty<ShadowShape>(),
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: true);
+
+        Assert.False(reg.TryGetRetailCellArray(entityId, out var cells));
+        Assert.Empty(cells);
+        Assert.Empty(reg.GetOwnerCells(entityId));
+        Assert.Empty(reg.GetRetailPartEntriesInCell(CellA));
+    }
+
+    [Fact]
+    public void RegisterMultiPart_RenderOnly_KeepWhenEmptyPreservesThePriorRegistration()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint entityId = 0x52u;
+        IReadOnlyList<ShadowShape> partArray = new[] { Bsp(0x0100_0062u, radius: 2f) };
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, Array.Empty<ShadowShape>(),
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: true, partArray: partArray);
+        Assert.True(reg.TryGetRetailCellArray(entityId, out var before));
+        Assert.Equal(new[] { CellA }, before);
+
+        // landblockId 0 (no seedCellId either) => DeriveOutdoorSeed returns 0
+        // => the retail keep-when-empty gate (pc:283540): neither product is
+        // touched.
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, Array.Empty<ShadowShape>(),
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, landblockId: 0u,
+            isStatic: true, partArray: partArray);
+
+        Assert.True(reg.TryGetRetailCellArray(entityId, out var after));
+        Assert.Equal(before, after);
+        Assert.NotEmpty(reg.GetRetailPartEntriesInCell(CellA));
+    }
+
+    [Fact]
+    public void RegisterMultiPart_RenderOnly_DeregisterClearsEveryProduct()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint entityId = 0x53u;
+        IReadOnlyList<ShadowShape> partArray = new[] { Bsp(0x0100_0063u, radius: 2f) };
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, Array.Empty<ShadowShape>(),
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: true, partArray: partArray);
+        Assert.True(reg.TryGetRetailCellArray(entityId, out _));
+
+        reg.Deregister(entityId);
+
+        Assert.False(reg.TryGetRetailCellArray(entityId, out var cells));
+        Assert.Empty(cells);
+        Assert.Empty(reg.GetRetailPartEntriesInCell(CellA));
+    }
+
+    [Fact]
+    public void UpdatePosition_RenderOnly_RecomputesTheRetailCellArrayAtTheNewPosition()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint entityId = 0x54u;
+        IReadOnlyList<ShadowShape> partArray = new[] { Bsp(0x0100_0064u, radius: 2f) };
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, Array.Empty<ShadowShape>(),
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: true, partArray: partArray);
+        Assert.True(reg.TryGetRetailCellArray(entityId, out var before));
+        Assert.Equal(new[] { CellA }, before);
+
+        var moved = new Vector3(42f, 12f, 50f); // 30 m away in X -> CellB
+        reg.UpdatePosition(entityId, moved, Quaternion.Identity, OffX, OffY, LbId);
+
+        Assert.True(reg.TryGetRetailCellArray(entityId, out var after));
+        Assert.Equal(new[] { CellB }, after);
+        Assert.DoesNotContain(
+            reg.GetRetailPartEntriesInCell(CellA),
+            e => e.EntityId == entityId);
+        var movedEntries = reg.GetRetailPartEntriesInCell(CellB)
+            .Where(e => e.EntityId == entityId).ToList();
+        Assert.Single(movedEntries);
+        Assert.Equal(0x0100_0064u, movedEntries[0].GfxObjId);
+        // Still no collision row after the move.
+        Assert.Empty(reg.GetOwnerCells(entityId));
+    }
+
+    // -------------------------------------------------------------------
+    // Chunk 5 closeout: a streaming reflood (RefloodOwnerForLandblock, the
+    // path landblock replacement commits and the Content builder's
+    // post-publication reflood both take) is retail's recalc_cross_cells
+    // over the SAME CPartArray, so the retail render product survives it.
+    // Before this pin the reflood re-registered from the collision shapes
+    // only and every reflooded owner vanished from the walk.
+    // -------------------------------------------------------------------
+
+    [Fact]
+    public void RefloodLandblock_KeepsTheRetailProductOfACollisionOwnerWithAPartArray()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint entityId = 0x60u;
+        IReadOnlyList<ShadowShape> collision = new[] { Bsp(0x0100_0070u, radius: 2f) };
+        IReadOnlyList<ShadowShape> parts = new[]
+        {
+            Bsp(0x0100_0070u, radius: 2f),
+            Bsp(0x0100_0071u, localPosition: new Vector3(0.5f, 0f, 0f), radius: 1f),
+        };
+
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, collision,
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: true, partArray: parts);
+        Assert.True(reg.TryGetRetailCellArray(entityId, out var before));
+        var beforeEntries = reg.GetRetailPartEntriesInCell(CellA)
+            .Where(e => e.EntityId == entityId).Select(e => e.GfxObjId).ToList();
+        Assert.Equal(new[] { 0x0100_0070u, 0x0100_0071u }, beforeEntries);
+
+        reg.RefloodLandblock(LbId);
+
+        Assert.True(reg.TryGetRetailCellArray(entityId, out var after));
+        Assert.Equal(before, after);
+        Assert.Equal(RetailCellArrayRoute.BoundingBox, reg.GetRetailCellArrayRoute(entityId));
+        var afterEntries = reg.GetRetailPartEntriesInCell(CellA)
+            .Where(e => e.EntityId == entityId).Select(e => e.GfxObjId).ToList();
+        Assert.Equal(beforeEntries, afterEntries);
+        // The collision product is untouched by the reflood as well.
+        Assert.Equal(new[] { CellA }, reg.GetOwnerCells(entityId));
+    }
+
+    [Fact]
+    public void RefloodLandblock_KeepsARenderOnlyOwner()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint entityId = 0x61u;
+        IReadOnlyList<ShadowShape> parts = new[] { Bsp(0x0100_0072u, radius: 2f) };
+
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, Array.Empty<ShadowShape>(),
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: true, partArray: parts);
+        Assert.True(reg.TryGetRetailCellArray(entityId, out _));
+
+        reg.RefloodLandblock(LbId);
+
+        // Still registered, still render-only, still in its cell: the empty
+        // collision shape list plus the retained part array is the
+        // render-only registration, not the "nothing supplied" deregistration.
+        Assert.True(reg.TryGetRetailCellArray(entityId, out var cells));
+        Assert.Equal(new[] { CellA }, cells);
+        var entries = reg.GetRetailPartEntriesInCell(CellA)
+            .Where(e => e.EntityId == entityId).ToList();
+        Assert.Single(entries);
+        Assert.Equal(0x0100_0072u, entries[0].GfxObjId);
+        Assert.Empty(reg.GetOwnerCells(entityId));
+    }
+
+    // -------------------------------------------------------------------
+    // S2 review fix round (2026-09-03): lifetime symmetry of the retail
+    // render product. remove_shadows_from_cells (0x00511230) removes the
+    // CShadowObj row AND the AddPartsShadow rows in one transaction, and
+    // recurses through children — every acdream path that drops one product
+    // drops the other.
+    // -------------------------------------------------------------------
+
+    private static int CountRows(ShadowObjectRegistry reg, uint cellId, uint entityId)
+        => reg.GetRetailPartEntriesInCell(cellId).Count(e => e.EntityId == entityId);
+
+    [Fact]
+    public void Suspend_ClearsTheRetailProduct_AndTheUnsuspendingMoveRepublishesIt()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint entityId = 0x70u;
+        IReadOnlyList<ShadowShape> parts = new[] { Bsp(0x0100_0080u, radius: 2f) };
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, parts,
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: false, partArray: parts);
+        Assert.Equal(1, CountRows(reg, CellA, entityId));
+
+        Assert.True(reg.Suspend(entityId));
+
+        Assert.False(reg.TryGetRetailCellArray(entityId, out _));
+        Assert.Equal(0, CountRows(reg, CellA, entityId));
+        Assert.Empty(reg.GetOwnerCells(entityId));
+        // The route and part array are retained for the republish.
+        Assert.Equal(RetailCellArrayRoute.BoundingBox, reg.GetRetailCellArrayRoute(entityId));
+
+        // A .None commit republishes at the RETAINED (suspended) cells for
+        // both products — the un-suspend path.
+        reg.CommitSetPosition(
+            entityId, Pos, Quaternion.Identity,
+            seedCellId: CellA, worldOffsetX: OffX, worldOffsetY: OffY,
+            action: PhysicsShadowCommitAction.None,
+            crossCellIds: ImmutableArray<uint>.Empty);
+
+        Assert.Equal(new[] { CellA }, reg.GetOwnerCells(entityId));
+        Assert.True(reg.TryGetRetailCellArray(entityId, out var cells));
+        Assert.Equal(new[] { CellA }, cells);
+        Assert.Equal(1, CountRows(reg, CellA, entityId));
+    }
+
+    [Fact]
+    public void AttachChild_AndDetachChild_AdvanceTheMutationRevision()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint rootId = 0x71u;
+        const uint childId = 0x72u;
+        IReadOnlyList<ShadowShape> rootParts = new[] { Bsp(0x0100_0081u, radius: 2f) };
+        reg.RegisterMultiPart(rootId, Pos, Quaternion.Identity, rootParts,
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: false, partArray: rootParts);
+
+        ulong before = reg.MutationRevision;
+        Assert.True(reg.AttachChild(childId, rootId, new[] { Bsp(0x0100_0082u) }));
+        Assert.True(reg.MutationRevision > before);
+
+        before = reg.MutationRevision;
+        Assert.True(reg.DetachChild(childId));
+        Assert.True(reg.MutationRevision > before);
+    }
+
+    [Fact]
+    public void RegisterMultiPart_OfAnAttachedChild_KeepsInheritingTheRootsCells()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint rootId = 0x73u;
+        const uint childId = 0x74u;
+        IReadOnlyList<ShadowShape> rootParts = new[] { Bsp(0x0100_0083u, radius: 2f) };
+        reg.RegisterMultiPart(rootId, Pos, Quaternion.Identity, rootParts,
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: false, partArray: rootParts);
+        Assert.True(reg.AttachChild(childId, rootId, new[] { Bsp(0x0100_0084u) }));
+        Assert.Equal(1, CountRows(reg, CellA, childId));
+
+        // An appearance update re-registers the child at its own (different)
+        // position with a NEW part array: retail never floods a child, so it
+        // keeps the root's CELLARRAY and only its parts change.
+        IReadOnlyList<ShadowShape> newParts = new[] { Bsp(0x0100_0085u, radius: 1f) };
+        reg.RegisterMultiPart(childId, new Vector3(42f, 12f, 50f), Quaternion.Identity, newParts,
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellB, isStatic: false, partArray: newParts);
+
+        Assert.True(reg.TryGetRetailCellArray(childId, out var childCells));
+        Assert.Equal(new[] { CellA }, childCells);
+        Assert.Equal(0, CountRows(reg, CellB, childId));
+        var rows = reg.GetRetailPartEntriesInCell(CellA).Where(e => e.EntityId == childId).ToList();
+        Assert.Single(rows);
+        Assert.Equal(0x0100_0085u, rows[0].GfxObjId);
+    }
+
+    [Fact]
+    public void RemoveLandblock_ClearsTheRetailProduct_IncludingRenderOnlyStatics()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint collidingId = 0x75u;
+        const uint renderOnlyId = 0x76u;
+        IReadOnlyList<ShadowShape> parts = new[] { Bsp(0x0100_0086u, radius: 2f) };
+        reg.RegisterMultiPart(collidingId, Pos, Quaternion.Identity, parts,
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: true, partArray: parts);
+        reg.RegisterMultiPart(renderOnlyId, Pos, Quaternion.Identity, Array.Empty<ShadowShape>(),
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: true, partArray: parts);
+        Assert.Equal(1, CountRows(reg, CellA, renderOnlyId));
+
+        reg.RemoveLandblock(LbId);
+
+        Assert.False(reg.TryGetRetailCellArray(collidingId, out _));
+        Assert.False(reg.TryGetRetailCellArray(renderOnlyId, out _));
+        Assert.Empty(reg.GetRetailPartEntriesInCell(CellA));
+        // Both statics ended with their landblock — nothing left to suspend.
+        Assert.False(reg.Suspend(collidingId));
+        Assert.False(reg.Suspend(renderOnlyId));
+    }
+
+    [Fact]
+    public void RetireOwnerFromLandblock_PrunesTheRetailRowsOfANonRootedOwner()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint entityId = 0x77u;
+        IReadOnlyList<ShadowShape> parts = new[] { Bsp(0x0100_0087u, radius: 2f) };
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, parts,
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: false, partArray: parts);
+        Assert.Equal(1, CountRows(reg, CellA, entityId));
+
+        reg.RetireOwnerFromLandblock(entityId, LbId);
+
+        Assert.Equal(0, CountRows(reg, CellA, entityId));
+        Assert.False(reg.TryGetRetailCellArray(entityId, out _));
+        Assert.Empty(reg.GetOwnerCells(entityId));
+        // A live owner survives the prefix retirement (it is still logically
+        // alive for the reload reflood), so it can still be suspended.
+        Assert.True(reg.Suspend(entityId));
+    }
+
+    [Fact]
+    public void ReplaceMultiPartPayload_WithAnEmptyPartArray_KeepsThePriorRows()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint entityId = 0x78u;
+        IReadOnlyList<ShadowShape> parts = new[] { Bsp(0x0100_0088u, radius: 2f) };
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, parts,
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: false, partArray: parts);
+
+        reg.ReplaceMultiPartPayload(entityId, Pos, Quaternion.Identity, parts,
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: false, partArray: Array.Empty<ShadowShape>());
+
+        // Never a cell-array claim with no drawable rows behind it.
+        Assert.True(reg.TryGetRetailCellArray(entityId, out var cells));
+        Assert.Equal(new[] { CellA }, cells);
+        Assert.Equal(1, CountRows(reg, CellA, entityId));
+    }
+
+    [Fact]
+    public void CommitSetPosition_None_MovesARenderOnlyOwnerToItsDestinationCell()
+    {
+        var reg = new ShadowObjectRegistry();
+        const uint entityId = 0x79u;
+        IReadOnlyList<ShadowShape> parts = new[] { Bsp(0x0100_0089u, radius: 1f) };
+        reg.RegisterMultiPart(entityId, Pos, Quaternion.Identity, Array.Empty<ShadowShape>(),
+            state: 0u, flags: EntityCollisionFlags.None, OffX, OffY, LbId,
+            seedCellId: CellA, isStatic: false, partArray: parts);
+        Assert.Equal(1, CountRows(reg, CellA, entityId));
+
+        // A render-only owner has no collision cells to republish from, so
+        // its "cell did not change" commit would otherwise freeze it at its
+        // registration cells forever (retail review F3): it travels with its
+        // destination cell instead (AD-117).
+        reg.CommitSetPosition(
+            entityId, new Vector3(42f, 12f, 50f), Quaternion.Identity,
+            seedCellId: CellB, worldOffsetX: OffX, worldOffsetY: OffY,
+            action: PhysicsShadowCommitAction.None,
+            crossCellIds: ImmutableArray<uint>.Empty);
+
+        Assert.True(reg.TryGetRetailCellArray(entityId, out var cells));
+        Assert.Equal(new[] { CellB }, cells);
+        Assert.Equal(0, CountRows(reg, CellA, entityId));
+        Assert.Equal(1, CountRows(reg, CellB, entityId));
+        Assert.Empty(reg.GetOwnerCells(entityId));
+    }
 }