acdream/docs/research/2026-06-05-render-residual-a-shipped-core-inside-render-handoff.md

# Handoff — Render Residual A SHIPPED; next = the CORE inside render (R1 completion) — 2026-06-05

> **Canonical pickup for the next (render) session. Read this FIRST.** Residual A (camera collision)
> is a faithful verbatim port of `SmartBox::update_viewer` — shipped, tested, user-kept. It made the
> render's viewpoint *accurate*, which **exposed** the real next problem with precision: the inside
> render does not flood/seal correctly from the (now-correct) viewer cell. The "step C" the user asked
> for is therefore **not** the handoff-era "C / outside-looking-in" — it is the **core inside render
> (R1 completion)**. Branch `claude/thirsty-goldberg-51bb9b`. PowerShell on Windows; launch logs are
> UTF-16 (`Select-String` / `rg --encoding utf-16-le`, NOT GNU grep).

---

## 0. TL;DR

- **SHIPPED (A):** verbatim `SmartBox::update_viewer` — indoor start-cell seated at the head-pivot
  (`AdjustPosition` → `find_visible_child_cell`) + the two fallbacks + cellId==0 snap-to-player.
  Commits `0ffc3f5` (spec) / `5177b54` (Core primitives) / `9e70031` (SweepEye orchestration). TDD,
  11 new tests, no regression. User-kept (chose "Keep it" over revert).
- **The live-capture finding that scoped A:** A's V1 sweep *already* contained the eye (`eyeInRoot=Y`
  99.75%, `viewerCell` never 0, indoor collide 97.6%). So A is a faithfulness completion, not a
  visible-bug fix. The dominant inside-cottage **bluish void / see-through-to-other-buildings is NOT
  the camera — it is the render seal.**
- **What A EXPOSED (the handoff's whole point):** the render roots at the **viewer cell**
  (`clipRoot = visibility.CameraCell`, GameWindow.cs:7322; Phase W V1 "one viewpoint"). A made that
  cell *accurate* (the eye's real, collided cell). So when you stand in the cellar but the eye is up
  in the room, `clipRoot = the room`, and the PVS flood from the room **does not reach the cellar** →
  **the cellar floor drops.** Before A, `viewerCell ≈ playerCell` (the sweep started from the feet
  cell), which *accidentally masked* this. The user accepted this interim floor-drop to keep the
  faithful viewpoint.
- **NEXT = the core inside render (R1 completion):** make `DrawInside` flood + seal correctly from the
  viewer cell. This fixes BOTH the **bleed** (point 1) AND the **floor** A exposed — they are the same
  family. The locked design already exists:
  [`docs/superpowers/specs/2026-06-02-render-pipeline-redesign-design.md`](../superpowers/specs/2026-06-02-render-pipeline-redesign-design.md).
- **Test baseline:** Core **1326 pass / 4 fail (documented) / 1 skip**; App **179 pass / 0 fail**.
  The 4 Core fails are pre-existing (2× `DoorBugTrajectoryReplay` LiveCompare, `BSPStepUpTests.D4`,
  `DoorCollisionApparatus`).

---

## 1. What shipped — Residual A (verbatim `SmartBox::update_viewer`, pc:92761)

| Commit | What | Layer |
|---|---|---|
| `0ffc3f5` | design spec (`docs/superpowers/specs/2026-06-05-residual-a-camera-collision-design.md`) | docs |
| `5177b54` | `CellTransit.FindVisibleChildCell` (CEnvCell::find_visible_child_cell pc:311397) + `PhysicsEngine.AdjustPosition` (CPhysicsObj::AdjustPosition pc:280009) | Core |
| `9e70031` | `ResolveResult.Ok` (surfaces `find_valid_position != 0`) + `PhysicsCameraCollisionProbe.SweepEye` orchestration (start-cell seating + fallback 1 + fallback 2 + cellId==0 snap-to-player) | Core + App |

The orchestration mirrors `update_viewer` end-to-end: indoor (`objcell_id >= 0x100`) seats the sweep's
start cell at the **head-pivot** via `AdjustPosition` (the cellar lip: feet in the low connector, head
up at floor level); sweep `pivot → sought-eye` from that start; on success `set_viewer(curr_pos)`,
`viewer_cell = curr_cell`; fallback 1 = `AdjustPosition(sought_eye)`; fallback 2 / no-cell = snap to
player, `viewer_cell = null`. `SweepEye` gained a `playerPos` arg (for the snap).

**Why A's visible payoff was nil this session (don't be surprised):** the seating only differs from the
feet cell when the feet are in a *thin connector* cell while the head is in a taller neighbour (the lip
— a transient). Two live captures: in the cottage room every frame had `start == cell` (0 seated of
80,605); in the cellar the seating *did* fire (1,687 frames, `start != cell`). No fallback ever fired
(`ok=False`: 0). So A is faithful + correct; its job was to make the viewpoint accurate, which it did.

## 2. The exposure (READ THIS — it is the bridge to the next phase)

The render roots + projects from **one viewpoint = the viewer cell** (Phase W V1, GameWindow.cs:7322,
7330-7333: *"the render root (clipRoot = the viewer cell). ONE viewpoint"*). `PortalVisibilityBuilder.Build(clipRoot, viewerEye, …)`
floods the PVS from `clipRoot`.

A changed `viewerCell` from `≈ playerCell` (V1, sweep from the feet cell) to **the eye's actual cell**
(seated at the pivot). Live proof, player in the cellar (`playerCell=0xA9B40174`):

```
[flap-cam] root=0xA9B40171 viewerCell=0xA9B40171 playerCell=0xA9B40174  eye=(155,12,96.5) player=(153,9,93)   ×1466 frames
```

`clipRoot = viewerCell = 0171` (the room, where the eye is) while the player is in `0174` (the cellar).
The PVS flood from the room **does not reach the cellar** → the cellar floor (the player's cell) is not
drawn → **missing floor**. This is exactly the spec's predicted symptom: §1.3 + §8 call the grey/missing
cellar floor a **sealing bug** (the closed cell mesh not covering pixels, OR the flood not reaching the
cell). **Cause unconfirmed — confirm it first (evidence-first, §4 below).**

The **bleed** (point 1: walls bluish, other buildings/particles/NPCs visible through them from inside)
is the same family: the inside path still draws the **whole outdoor world** then layers cell shells on
top, instead of retail's "inside → `DrawInside` only" (spec §2). A faithful `DrawInside` makes the bleed
impossible *by construction*.

## 3. The reframing — "C" is the CORE inside render, not outside-looking-in

The handoff-era residual letters (A camera / B particles / **C outside-looking-in**) map onto the locked
render spec's phases as: A camera (DONE), B → **R1b** (#104 particles), **C → R2** (`DrawPortal`,
street→interior). **R2 is a LATER phase.** The visible problems the user is hitting — the bleed AND the
floor A exposed — are **R1 (the core per-cell `DrawInside` flood+seal)**, which shipped only *partially*
(2026-06-03: the flap fix + basic shells + inside-looking-out, but NOT the "inside → DrawInside only"
inversion, NOT the general-case flood from `viewerCell != playerCell`). **The next session finishes R1.**

## 4. The job (next session) — evidence-first, then verbatim PView

1. **Read the locked design + its 4 research docs (in the spec's "Read first" list):**
   `docs/superpowers/specs/2026-06-02-render-pipeline-redesign-design.md` →
   `docs/research/2026-06-02-render-pipeline-redesign-handoff.md` (root cause, the three-gate failure) →
   `…-retail-render-pipeline-full-reference.md` (the PView + `DrawCells` seal) →
   `…-acdream-render-pipeline-inventory-and-failures.md` (the `WbDrawDispatcher.cs:1756` bypass, the
   parallel BFS, the terrain Skip model) → `…-render-reference-crosscheck.md` (why WB two-pipe is wrong).
2. **Confirm the floor cause FIRST (do NOT guess — spec §8):** launch with `ACDREAM_PROBE_FLAP=1`
   `ACDREAM_PROBE_VIS=1` `ACDREAM_PROBE_SHELL=1`; stand in the cellar, get the eye up in the room
   (`viewerCell=room`, `playerCell=cellar`). Read `[vis]` (does `OrderedVisibleCells` include the cellar
   when rooted at the room?) + `[shell]` (does the cellar shell draw?) + dump the cellar EnvCell mesh
   (is the floor polygon present + front-facing?). This decides: **PVS-flood-not-reaching** vs
   **cell-mesh-not-sealing**. Get a screenshot EARLY (memory `render-one-gate`).
3. **Port the PView seal/flood verbatim (spec §2 + §4):** the binary top-level decision (inside →
   `DrawInside` only — removes the global outdoor pass → kills the bleed by construction) + the per-cell
   `DrawInside` loop (landscape-through-door → conditional Z-only clear → per-cell shells → per-cell
   objects → per-cell particles). Retail anchors: `RenderNormalMode` 0x453aa0, `PView::DrawInside`
   0x5a5860, `ConstructView` 0x5a57b0, `DrawCells` 0x5a4840 (spec §11 has the full index).
4. **VALIDATE — visual gate (spec R1 gate):** Holtburg cottage + cellar — sealed interior (opaque walls,
   **solid floor**, ceiling), sky/terrain through the door only, **no bluish void, no bleed** (no other
   buildings/particles/NPCs through walls), no terrain under the floor. Build + Core(1326p/4f/1s)/App(179p) green.

## 5. KEEP / DON'T-REDO

**KEEP (do not reopen):**
- **Residual A** (the 3 commits). The viewer cell is now accurate — that is the *input* the render needs.
  Do NOT revert it to mask the floor (the user explicitly chose to keep the faithful viewpoint).
- The Phase W V1 "one viewpoint" (clipRoot = viewer cell, project from the eye) — GameWindow.cs:7322-7338.
- The Stage-1 membership port + the blue-hole fix (`UpdatePlayerCurrCell`, player-only render-root).
- `PortalVisibilityBuilder` / `ClipFrame` / `EnvCellRenderer` / `TerrainModernRenderer` / the WB mesh
  pipeline (spec §3 KEEP).

**DON'T:**
- Don't re-add a `CurrCell` write inside `ResolveWithTransition` / `ResolveCellId` (the blue-hole clobber).
- Don't reintroduce the WB two-pipe stencil / `isInside` gate / AABB grace-frame for the root (spec §8).
- Don't relax the faithful terrain `Skip` to "fix" the grey floor (spec §1.3 — it's a sealing bug, not a
  terrain-clip bug).
- Don't jump to R2 (outside-looking-in / `DrawPortal`) — R1 (the inside seal+flood) is first.

## 6. KEY FILES + ANCHORS

```
RENDER (the next phase)
  src/AcDream.App/Rendering/GameWindow.cs (OnRender ~7300-7610)   ← clipRoot=viewerCell (7322); binary decision lives here
  src/AcDream.App/Rendering/PortalVisibilityBuilder.cs            ← the PVS BFS (KEEP; the flood to harden/port)
  src/AcDream.App/Rendering/InteriorRenderer.cs                   ← per-cell DrawInside loop (partial)
  src/AcDream.App/Rendering/EnvCellRenderer.cs                    ← per-cell shell mesh (Render(pass,{cellId}))
  src/AcDream.App/Rendering/WbDrawDispatcher.cs (~1756)           ← the ParentCellId==null bypass to delete
  src/AcDream.App/Rendering/ClipFrameAssembler.cs / CellVisibility.cs
  docs/superpowers/specs/2026-06-02-render-pipeline-redesign-design.md  ← LOCKED design (§2 model, §4 seal, §7 phases, §11 anchors)

CAMERA (A — shipped, the input)
  src/AcDream.App/Rendering/PhysicsCameraCollisionProbe.cs        ← SweepEye = verbatim update_viewer
  src/AcDream.Core/Physics/CellTransit.cs  FindVisibleChildCell   ← pc:311397
  src/AcDream.Core/Physics/PhysicsEngine.cs AdjustPosition        ← pc:280009

PROBES
  ACDREAM_PROBE_FLAP=1   [flap-cam] root/viewerCell/playerCell/eyeInRoot  +  [flap] PVS BFS  +  [flap-sweep] camera (start vs cell, ok)
  ACDREAM_PROBE_VIS=1    [vis] OrderedVisibleCells + OutsideView
  ACDREAM_PROBE_SHELL=1  [shell] per-cell shell draw
  ACDREAM_PROBE_CELL=1   [cell-transit] player CellId changes
```

## 7. RUNNING THE CLIENT (PowerShell; `+Acdream` spawns in the Holtburg cottage)

```powershell
$env:ACDREAM_DAT_DIR="$env:USERPROFILE\Documents\Asheron's Call"; $env:ACDREAM_LIVE="1"
$env:ACDREAM_TEST_HOST="127.0.0.1"; $env:ACDREAM_TEST_PORT="9000"
$env:ACDREAM_TEST_USER="testaccount"; $env:ACDREAM_TEST_PASS="testpassword"
$env:ACDREAM_PROBE_FLAP="1"; $env:ACDREAM_PROBE_VIS="1"; $env:ACDREAM_PROBE_SHELL="1"
dotnet run --project src\AcDream.App\AcDream.App.csproj --no-build -c Debug *>&1 | Tee-Object -FilePath launch.log
```
Build green BEFORE launching. Logs are UTF-16. Close gracefully (✕ / Alt+F4) so ACE clears the session in ~3-5s.

## 8. KICKOFF PROMPT (copy-paste for the next session)

```
Continue acdream M1.5 render work: the CORE INSIDE RENDER (R1 completion) — make DrawInside flood + seal
correctly from the viewer cell so the cottage/cellar interior is SEALED: no bluish void, no see-through-to-
other-buildings BLEED, and the CELLAR FLOOR draws. This is what the user means by "step C" — it is NOT the
handoff-era "C / outside-looking-in" (that is R2, a later phase). Branch claude/thirsty-goldberg-51bb9b
(do NOT branch/worktree; do NOT push without asking; NEVER git stash/gc). PowerShell on Windows; launch
logs are UTF-16 (Select-String / rg --encoding utf-16-le, NOT GNU grep). Use superpowers:systematic-
debugging; the render redesign DESIGN is already LOCKED (read the spec), so this is execution + an
evidence-first floor-cause confirmation, not a re-brainstorm.

READ FIRST (in order):
1. docs/research/2026-06-05-render-residual-a-shipped-core-inside-render-handoff.md  (THIS handoff — what
   A shipped, what A EXPOSED §2, the reframing §3, the job §4, KEEP/DON'T §5, files §6).
2. docs/superpowers/specs/2026-06-02-render-pipeline-redesign-design.md  (the LOCKED design — §2 the one
   model, §4 the seal mechanics, §7 phases/gates, §11 decomp anchors) + its 4 "Read first" research docs.
3. memory: reference_render_pipeline_state.md, feedback_render_one_gate.md,
   feedback_render_downstream_of_membership.md, feedback_verify_render_seal_before_layering.md.

STATE: Residual A (camera collision) SHIPPED + user-kept (commits 0ffc3f5/5177b54/9e70031) — verbatim
SmartBox::update_viewer; the viewer cell is now ACCURATE. That accuracy EXPOSED the next problem: the
render roots at the viewer cell (clipRoot=visibility.CameraCell, GameWindow.cs:7322), and the PVS flood
from the viewer cell does NOT reach the player's cell when they differ (eye in the room, player in the
cellar → clipRoot=room → cellar floor not drawn). Same family as the bleed (the inside path still draws
the whole outdoor world instead of "inside → DrawInside only").

THE JOB (evidence-first, then verbatim PView):
1. Confirm the floor cause FIRST (spec §8 flags it unconfirmed): launch with ACDREAM_PROBE_FLAP/_VIS/_SHELL,
   stand in the cellar with the eye up in the room (viewerCell=room, playerCell=cellar), read [vis]
   (is the cellar in OrderedVisibleCells when rooted at the room?) + [shell] + dump the cellar EnvCell
   mesh (floor poly present + front-facing?). Decide PVS-flood-not-reaching vs cell-mesh-not-sealing.
   Screenshot EARLY.
2. Port the PView seal/flood verbatim (spec §2 + §4): the binary top-level decision (inside → DrawInside
   ONLY — removes the global outdoor pass → kills the bleed by construction) + the per-cell DrawInside loop
   (landscape-through-door → conditional Z-only clear → per-cell shells → per-cell objects → per-cell
   particles). Anchors: RenderNormalMode 0x453aa0, PView::DrawInside 0x5a5860, ConstructView 0x5a57b0,
   DrawCells 0x5a4840.
3. VALIDATE — visual gate: Holtburg cottage + cellar sealed (opaque walls, SOLID FLOOR, ceiling), sky/
   terrain through the door only, NO bluish void, NO bleed. Build + Core(1326p/4f/1s)/App(179p) green.

DON'T: revert A to mask the floor (user chose to keep the faithful viewpoint); re-add a CurrCell write in
ResolveWithTransition/ResolveCellId (blue-hole); reintroduce the WB two-pipe / isInside gate / AABB grace
(spec §8); relax the faithful terrain Skip (spec §1.3 — it's a sealing bug); jump to R2 (outside-looking-in)
before R1 (the inside seal+flood) is done.

TEST BASELINE: Core 1326 pass / 4 fail (documented: 2× DoorBugTrajectoryReplay LiveCompare, BSPStepUpTests.D4,
DoorCollisionApparatus) / 1 skip. App 179 pass / 0 fail. Branch HEAD 9e70031 (+ this handoff commit).
```