# T6 (BR-7) SHIPPED + T5 gate verdict + post-T5 fixes — session handoff (2026-06-11)

**Branch:** `claude/thirsty-goldberg-51bb9b`, HEAD `0e6e24f`. **Nothing on main.**
**Suites (all green):** Core **1416 / 0 / 2 skips** (skip 1 = pre-existing
`PvsConformanceTests`; skip 2 = `BSPStepUpTests.D4` with the #116 reference),
App **227**, UI **420**, Net **294**.

This session: (1) shipped **T6 / BR-7** — the A6.P4 per-cell shadow collision
architecture, the last code phase of the holistic building-render port;
(2) ran **T5**, the single comprehensive user visual gate (PARTIAL PASS —
the entire collision half passed, four render artifacts filed); (3) fixed
**#117** (aperture punch-through), armed **#120** (flood-growth tripwire),
narrowed **#118** (exit-vanish). The holistic port (BR-1…BR-7) is now
**code-complete and partially visually validated**.

Read first, always: `claude-memory/project_render_pipeline_digest.md` +
`claude-memory/project_physics_collision_digest.md` (both updated this
session — current-truth banners on top).

---

## 1. The session's commit ledger (oldest first)

| SHA | What |
|---|---|
| `6ec4cde` | T6 C1 — signed `OtherPortalId` + the `>= 0` building-transit gate (`check_building_transit` 0x0052c5d0; BN renders the comparison unsigned — Ghidra-proven sign extension; wire 0xFFFF = −1 = no reciprocal portal). Multi-sphere `CheckBuildingTransit` overload + `hitsInteriorCell` out. |
| `abf36e2` | T6 C2 — `CellTransit.BuildShadowCellSet`: the registration-side sphere-overlap portal flood (verbatim `find_cell_list` 0x0052b4e0 via `calc_cross_cells(_static)`). Indoor seed → that cell + growing-array walk; outdoor seed → block-crossing `AddAllOutsideCells`; outdoor cells in the walk run the building bridge; statics get the `do_not_load` prune ({seed} ∪ stab list — also strips outdoor cells, retail-faithful). The spec's VisibleCellIds rule was REFUTED (WF1) — no visibility list anywhere in shadow placement. 11 unit tests. |
| `dbfbf85` | T6 C3 (FUSED — the BR-2 half-port lesson: registration+query co-dependent) — registry rewritten to flood-seeded per-cell lists (CylSphere flood rule: base pt + cyl radius, cap 10, 0x0052b9f0; keep-when-empty pc:283540; `RefloodLandblock` streaming hook = retail `init_objects → recalc_cross_cells`); **building shells left the registry** (per-LandCell channel: `Transition.FindBuildingCollisions` = `CSortCell::find_collisions` 0x005340a0 → `find_building_collisions` 0x006b5300; ONE building per ORIGIN landcell, `init_buildings` 0x0052fd80 verified verbatim + ACE cross-ref; only caller is 0x005340aa); **query strictly per-cell** (`FindObjCollisionsInCell` = `find_obj_collisions` 0x0052b750; insert order env→building→objects on the primary, then `CheckOtherCells` runs env+building+objects per OTHER cell with the carried-cell advance AFTER all object passes — `transitional_insert` 0x0050b6f0 OK_TS case); placement weakening `center_solid=0` when `BldgCheck && HitsInteriorCell` (0x0053a82e / 0x005399d8; both fields added to SpherePath, rebuilt at every cell-array build). **DELETED: the radial 9-LB sweep, the +5 m query pad, the b3ce505 indoor gate, the isViewer exemption.** 3 of the 4 #99-era reds flipped green (door apparatus → `…_Blocks`, tick-13558 asserts the door BLOCKS, tick-22760 pins the blocking invariant). |
| `ca4b482` | T6 C4 — A6.P5 `hasExitPortal` topology widening DELETED (outside cells enter the collision array ONLY on the retail straddle — same flag as the membership pick; the WF1 correction "re-gate, don't delete" implemented); **#90 stickiness REMOVED** (dead code — `ResolveCellId`'s only caller is the cache-null test fallback; the ordered-pick hysteresis owns doorway behavior). Two old A6.P5 pins inverted to retail truth. |
| `60c1070` | docs — T6 ship closeout: #99/#90 closed in ISSUES, #97 likely-close note, **#116 filed** (slide-response family), plan stamped. |
| `af5d424` | docs — **T5 gate verdict** (§3 below): #108/#109/#97 closed (user-confirmed), #117–#120 filed. |
| `2d15084` | **#120 armed** — tripwire self-attribution (`DumpPropagationChain`: root, eye, per-cell frequency, 24-entry chain tail) + `ConvergenceTripwireCount` observable + 2 dat-backed convergence sweeps as regression pins (3024 builds, 0 firings — production-only ingredients suspected). Retail finding: retail RECURSES natively too (`AddViewToPortals → FixCellList → AdjustCellView`, 0x005a52d0/0x005a5250/0x005a5770, no depth guard) — depth-128 = slow-convergence laps, not necessarily a true loop. |
| `478c549` | **#117 FIXED** — depth-gated punch (§4 below). |
| `0e6e24f` | docs — **#118 narrowed** (§5 below): two suspects exonerated by read; candidates + exit-walk harness design recorded in ISSUES. |

---

## 2. T6 / BR-7 — what the architecture is now (one paragraph)

Objects register into the EXACT cells their collision footprint overlaps,
computed once at registration by the retail sphere-overlap portal flood
(`BuildShadowCellSet`); a door straddling a threshold lands in BOTH the
outdoor landcell and the vestibule list. The collision query is strictly
per-cell (`GetObjectsInCell`) at retail's two sites — the primary insert
(env → building → objects) and `check_other_cells` (the same per OTHER
overlapped cell), with the carried-cell advance after all object passes.
Building shells are NOT shadow objects: an outdoor LandCell carries at most
one building reference (its origin cell) and runs the shell part-0 BSP
through `FindBuildingCollisions` with the `bldg_check`/`hits_interior_cell`
placement weakening. There is no spatial radius anywhere in the query path
— cell membership IS the broad phase. The b3ce505 stopgap, the A6.P5
widening, and the #90 stickiness are all gone.

**#116 (filed):** tick-22760's lateral-slide loss + BSPStepUp D4's
first-frame slide are a PRE-EXISTING slide-response family (probes prove
the cell-set layer innocent; BR-7 left both byte-identical). Fix shape:
ONE oracle-driven pass over `SlideSphere` + the first-contact frame
(`get_object_info` pc:279992 only seeds the NEXT frame). Do NOT patch the
degenerate-offset guard ad hoc.

---

## 3. T5 verdict (the user's reports are AXIOMS)

**✅ PASSED:** doors block both ways incl. off-center (#99 visual); cellar
descent/ascent clean + #108 grass-sweep GONE; interiors stable through
doorways incl. edge-on; inn 2nd floor clean (#97 CLOSED); #109 far-door
oscillation GONE; formerly-popping stairs now STABLE at all ranges
(the distance-pop class is dead). Rain-indoors not verifiable (clear).

**❌ Filed:**
- **#117** — aperture-shaped see-through: doors/interiors visible through
  terrain hills + through nearer buildings. → FIXED this session (§4).
- **#118** — character clipped + vanishes for a moment when exiting houses
  (viewer-indoor/player-outdoor window). → narrowed (§5), fix queued.
- **#119** — old tower: stair parts invisible (pre-existing, "same issue as
  before"; the tower stairs ARE visible in retail — user axiom) + an
  extraneous water barrel. **Lead from the T5 log:** exactly two
  `[up-null] upload returned null for 0x00010002B4 / 0x00010008A8 — caching
  EMPTY render data (permanently invisible)` lines at startup
  (`t5-gate-launch.log:33-34`, untracked in the worktree root). Untouched.
- **#120** — `[pv-ERROR] in-place propagation tripwire at depth 128` on
  cottage cells 0x…0175/0174/0162 during normal play (T2 invariant
  tripwire). → armed for self-attribution (§1, `2d15084`); wait for the
  next natural firing (any launch's log will carry the chain dump).

---

## 4. #117 — the fix that needs the re-gate

Decomp-settled root cause: retail's `DrawPortalPolyInternal` (0x0059bc90)
draws the punch with **DEPTHTEST_ALWAYS** + per-vertex far-Z (0.99999899,
`maxZ1` bit0) — it stomps ANY occluder depth unconditionally. Retail is
safe only because its outdoor pass is **painter's-ordered far→near**:
anything nearer redraws after the punch. Our z-buffered MDI frame has no
such order → the far house's aperture punch erased the near house's wall /
the hill's depth, and interiors + door entities (dynamics drawn last)
painted through — both #117 shapes.

Fix (`478c549`, `PortalDepthMaskRenderer`): the punch is now two passes —
**A)** stencil-mark where the aperture fan passes LEQUAL at its true depth
biased 0.0005 NDC toward the viewer (≈6 cm at 5 m; keeps #108's
terrain-hugging-the-door case punched), no depth write; **B)** far-Z write
with depth ALWAYS, stencil-gated EQUAL 1, zeroing stencil as it goes
(self-cleaning). The frame order guarantees correctness: terrain + ALL
building shells draw in the landscape stage BEFORE `DrawExitPortalMasks`,
so pass A tests against the real occluders. The SEAL (interior roots)
stays retail-verbatim single-pass (it runs right after the gated full
depth clear — nothing nearer to stomp). `WindowOptions` now requests
8 stencil bits explicitly. The stale "RESERVED — unwired" banner on the
class was corrected (T1 wired it via `DrawRetailPViewPortalDepthWrite`).

**Acceptance = the focused re-gate:** downhill door check, behind-house
openings, AND #108 cellar stays clean (the bias is the only regression
surface).

---

## 5. #118 — narrowed; the exit-walk harness is the next step

Exonerated by read: the draw partition (the local player carries
ServerGuid → Dynamics, never dropped) and entity-cell staleness
(`pe.ParentCellId = result.CellId` syncs per tick, GameWindow ~6855).

Live candidates (the doorway-crossing decision stack), in order:
1. **Eye/cell incoherence under camera damping** — the render root is the
   sweep's `RetailChaseCamera.ViewerCellId` while the projection eye
   (`camPos`) is the DAMPED position; during a crossing they can disagree
   by the damping lag. This is the already-VERIFIED #115/BR-8a divergence
   (retail damps FROM the published collided viewer; we damp from our own
   damped eye) — fixing BR-8a may fix #118 outright.
2. **Exit-portal side test at the threshold** — eye ε-outside the door
   plane while the root is still the interior cell →
   `CameraOnInteriorSide` culls the exit portal → OutsideView EMPTY →
   `SphereVisibleOutside` culls ALL outdoor dynamics (the player) for
   those frames. Retail's `AdjustPosition` demotes the viewer cell to
   outdoor the same moment the point exits (`seen_outside →
   adjust_to_outside`), making the inconsistent state structurally brief.
3. The doorway-aperture cone tightness for an outdoor player + indoor
   viewer.

**Next step (apparatus, not guessing — 3 hypotheses = build the
harness):** a deterministic exit-walk harness over the corner-building
cells (`CornerFloodReplayTests` infrastructure): per step of an eye+player
path crossing the doorway, drive the production decision stack headlessly
— viewer-cell resolution → `PortalVisibilityBuilder.Build(root)` →
`ViewconeCuller.Build` → the exact `DrawDynamicsLast` visibility predicate
— and assert the player sphere stays visible on every step. All CPU; the
failing step pins which candidate fires. Full design in the ISSUES #118
entry.

---

## 6. Watchouts / DO-NOT-RETRY for the next session

- **No radial/spatial sweeps back into `ShadowObjectRegistry`**, no
  topology-based outside-add, no gates — cell membership IS the broad
  phase; the straddle flag is live-binary verified. (Physics digest rules.)
- **Do not patch the `SlideSphere` degenerate-offset guard ad hoc** —
  #116 wants the oracle read first.
- **The punch must stay depth-gated.** Reverting to bare ALWAYS without
  painter's ordering re-opens #117 by construction.
- **#120: don't tune the tripwire constant** (128). The chain dump is the
  lead; retail's own recursion has no guard — the fix will be about WHY
  convergence is slow (dedup/merge admitting near-duplicates per lap), not
  about the limit.
- The two convergence sweeps in `CornerFloodReplayTests`
  (`PortalPlaneCrossings_…` / `InCellDirectionSweep_…`) are regression
  pins — keep green.
- **Building channel is origin-cell-only** (retail-verbatim,
  `init_buildings` + ACE cross-checked). If the re-gate shows soft wall
  collision on a LARGE building, first write the dat conformance fact
  (shell extent vs origin landcell for Holtburg models) before touching
  the dispatch.
- The 4 GameWindow registration sites pass `seedCellId:`; live entities
  seed from the wire cell id; `IsBuildingShell` entities skip the registry
  entirely. Don't re-add them.
- xunit swallows `Console.WriteLine` — use ITestOutputHelper or %TEMP%
  for harness diagnostics.

## 7. New apparatus (this session)

| Tool | Where | Purpose |
|---|---|---|
| `PortalVisibilityBuilder.ConvergenceTripwireCount` | static, test-visible | #120 observable; both Build + look-in sites |
| `DumpPropagationChain` | fires with the tripwire | root + eye + per-cell frequency + 24-entry chain tail |
| `PortalPlaneCrossings_InPlacePropagationConverges` | CornerFloodReplayTests | ±6 cm sweep across every portal plane, both seed sides |
| `InCellDirectionSweep_InPlacePropagationConverges` | CornerFloodReplayTests | 3×3×2 in-cell eye grid × 8 yaw × 3 pitch (3024 builds) |
| `Diagnostic_Tick22760_DumpEngineInternals` | DoorBugTrajectoryReplayTests | #116 repro dump (door found + BSP-only dispatched correctly) |
| `[bldg-channel]` probe | `Transition.FindBuildingCollisions` | per-channel-hit line under `ACDREAM_PROBE_BUILDING` |
| `t5-gate-launch.log` | worktree root (untracked) | the T5 session log — `[up-null]` ×2 + `[pv-ERROR]` ×3 evidence |

## 8. Next-session work order (work-order autonomy: drive, don't ask)

1. **#118** — build the exit-walk harness; fix what it pins (BR-8a is the
   likely fix if candidate 1 confirms — the retail damping shape is
   already verified in the plan).
2. **#119** — chase the `[up-null]` pair (identify the two models; why
   `ObjectMeshManager`'s upload returned null; whether the
   permanently-invisible cache should retry); then the barrel
   (static-inclusion question).
3. **Focused re-gate with the user** (one launch, short list): downhill
   door check + behind-house openings (#117), house-exit character
   (#118), tower stairs + barrel (#119), #108 cellar stays clean, and
   grep the log for `[pv-ERROR]` chain dumps (#120's self-attribution).
4. Then per the plan: BR-8a camera (may already be consumed by #118),
   #116 oracle pass, roadmap/milestones closeout of the holistic port.

---

## 9. Paste-ready next-session prompt

```
Pick up acdream as a SENIOR 3D ENGINE DEVELOPER on the POST-T5 residual
fixes of the holistic building-render port. Worktree branch
claude/thirsty-goldberg-51bb9b, HEAD 0e6e24f. Nothing goes to main.

STATE: the holistic port is CODE-COMPLETE and T5-gated (partial pass).
T6/BR-7 (per-cell shadow collision) SHIPPED — #99/#90/#97/#108/#109 all
CLOSED (user-confirmed at T5). #117 (aperture punch-through occluders)
FIXED 478c549 — pending visual re-gate. Suites green: Core 1416/0/2skip,
App 227, UI 420, Net 294.

READ FIRST (in order):
1. Memory digests: project_render_pipeline_digest +
   project_physics_collision_digest (current-truth banners on top; the
   DO-NOT-RETRY tables APPLY — note the new no-radial-sweep /
   no-topology-add / punch-stays-depth-gated / #116-oracle-first rules).
2. docs/research/2026-06-11-t6-br7-shipped-t5-gate-post-t5-handoff.md
   (THE handoff: T6 architecture summary, T5 verdict, #117 fix detail,
   #118 narrowing + harness design, #119 up-null lead, #120 armed
   tripwire, watchouts, work order).

DO NEXT — #118 (character clipped+vanishes on house exit):
build the deterministic exit-walk harness designed in ISSUES #118 /
handoff §5 (CornerFloodReplayTests infrastructure; per step of an
eye+player doorway-crossing path, drive viewer-cell resolution →
PortalVisibilityBuilder.Build → ViewconeCuller → the DrawDynamicsLast
visibility predicate; assert the player sphere stays visible). The
failing step pins one of three candidates (handoff §5); candidate 1
(eye/cell incoherence under damping) is the verified #115/BR-8a
divergence — if it confirms, the fix is BR-8a's retail damping shape
(damp FROM the published collided viewer). 3 hypotheses already exist —
apparatus first, no speculative fixes.

THEN — #119 (tower stairs + barrel): chase the [up-null]
0x00010002B4/0x00010008A8 permanently-invisible upload failures
(t5-gate-launch.log:33-34) before any draw-path theorizing; the barrel
is a separate static-inclusion question.

THEN — the FOCUSED RE-GATE with the user (one launch, short checklist):
downhill door check + behind-house openings (#117), house-exit character
(#118), tower stairs + barrel (#119), #108 cellar stays clean; grep the
log for [pv-ERROR] chain dumps (#120 self-attributes on its next firing).
User retail reports are AXIOMS; no per-artifact live-probing.

Build + test green per commit. Baselines: App 227 / Core 1416 + 2 skips
/ UI 420 / Net 294.
```