The post-Wave-5 indoor branch chaos (flickering, missing walls, GPU 100%,
~10 FPS) is caused by two interconnected pool-management bugs in
EnvCellRenderer that line-by-line WB comparison surfaced in 30 minutes.
Neither was found by the five post-Wave-5 speculative fixes because none
of them inspected the pool path.
Bug #1 — GetPooledList missing list.Clear():
The reuse branch returned pool lists with prior-frame data still inside.
PrepareRenderBatches' merge phase pattern `gfxDict[k] = list; list.AddRange(...)`
assumes empty lists. Without Clear(), lists grow unbounded each frame, GPU
draws cumulative instance counts, and per-instance transforms become a stew
of past + present data. Mirrors WB ObjectRenderManagerBase.cs:1221-1233.
Bug #2 — Render uses snapshot.BatchedByCell.Count instead of PostPreparePoolIndex:
The snapshot author dropped WB's PostPreparePoolIndex field calling it
"scenery-only," then "compensated" in Render by setting _poolIndex to the
cell count. The cell count has no relation to the pool — Prepare may have
used 50+ pool lists for an 18-cell scene. Render's filter-path GetPooledList
then returns lists that ARE in snapshot.BatchedByCell, corrupting the snapshot
mid-Render. Restoring PostPreparePoolIndex (WB VisibilitySnapshot.cs:31)
correctly places Render's pool cursor past the snapshot's owned region.
Bug #3 (minor) — PopulateRecursive hardcoded isSetup:false for nested parts:
Setup IDs use high-byte 0x02 (per retail). WB ObjectRenderManagerBase.cs:813
checks `(partId >> 24) == 0x02` to detect nested Setups. Our port always
passed isSetup:false, silently dropping any nested Setup (its TryGetRenderData
returns IsSetup=true, Render's `!IsSetup` guard skips the draw). Probably
rare in EnvCells but fixed for completeness.
Regression coverage:
- GetPooledList_ReusedList_IsClearedBeforeReturn — would have failed pre-fix
- GetPooledList_FreshList_IsAlwaysEmpty — sanity check
- Snapshot_PostPreparePoolIndex_IsInitSettable — compile-time guarantee
- Snapshot_PostPreparePoolIndex_DefaultsToZero — defensive default
86/86 App tests pass. Build green. The fix is the audit's primary
deliverable; the GL state probe option-1 apparatus follows in a separate
commit as defense-in-depth for any unidentified residual issue.
Full audit + WB cross-reference in
docs/research/2026-05-28-a8-env-cell-renderer-audit-findings.md.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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