Followed up the geometry-gap diagnosis with a wider polygon search.
Result: the cottage's north exterior wall east of doorway DOES exist
in cottage GfxObj 0x01000A2B (polys 0x0032, 0x0033) at
world X=[133.5, 136.3], Y=17.10, Z=[94, 97], normal +Y. Symmetric
polys cover the west side and above the doorway lintel.
The wall SHOULD block sphere at X=133.655 (sphere west edge at 133.175
overlaps wall X range; sphere south edge at 17.11 aligns with wall
at Y=17.10).
New hypothesis: the bug is sphere-vs-corner collision at the meeting
point of cell 0x0150's east wall (X=133.5, Y=[16.5, 17.1]) and the
cottage's north exterior wall (X=[133.5, 136.3], Y=17.10). Cell
transit data shows sphere going from X=132.859 entering alcove to
X=134.022 leaving alcove — sphere reached X=134.022 INSIDE cottage
geometry somehow. The sliding along the slab east face (cn=(+1,0,0)
in captured tick 3254) gradually pushes sphere east. Eventually it
shifts past X=133.5 — the corner where alcove east wall meets cottage
north wall. The corner-handling in our BSP collision may incorrectly
let the sphere slide past, or the alcove cell's east wall and cottage
GfxObj's north wall don't compose correctly at the corner.
Diagnostic apparatus extensions:
- HoltburgLandblockStatics_DatInspection: dumps LandBlockInfo for
landblock 0xA9B4. Shows 114 stabs + 12 buildings. The cottage IS
Building[6] with modelId=0x01000A2B (the GfxObj we already loaded).
- Diagnostic_CottagePolys_NearWalkthroughPosition: widened search
reveals the cottage's full north exterior wall geometry.
- HoltburgCottage_CellPortals_DatInspection: extended with cell
PhysicsPolygon world-frame dump (already in prior commit).
Full updated handoff: docs/research/2026-05-25-door-bug-inside-out-geometry-gap.md
Next-session move: add a "sphere walks +Y from inside alcove at
X near 133" test. If harness slides past the corner like production,
investigate BSPQuery's sphere-vs-edge case. If harness blocks at
corner, the bug is elsewhere (cell 0x0150 BSP not queried, or
cottage GfxObj BSP traversal misses the wall poly).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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