Built three new tests to investigate the inside-out asymmetric collision
that persists after the AddAllOutsideCells coord fix:
1. Directional_OutsideIn_SouthApproach_BlocksAtSlabSouthFace — sphere
south of door moving NORTH; expects block with cn.Y less than -0.5
2. Directional_InsideOut_NorthApproach_BlocksAtSlabNorthFace — sphere
north of door moving SOUTH; expects block with cn.Y greater than +0.5
3. Geometric_DoorSlabZRange_AbovePlayerSphereTop — pins the slab Z
range vs sphere top math
BOTH directional tests PASS — collision is symmetric at unit-test level.
The asymmetric production bug therefore comes from something the unit
tests do not capture (multi-tick state, cell-tracking flicker, walkable
polygon edge interactions).
The geometric pin test reveals the real story: Setup 0x020019FF places
the part-0 BSP slab 1.275 m ABOVE the entity origin via
PlacementFrames[Default][0].Origin. With the cottage door entity at
world Z=94.1, the slab world Z range is [95.375, 97.865]. Player sphere
top reaches Z=95.20. The slab BOTTOM is 0.175 m ABOVE the sphere top —
the slab NEVER collides with the player.
The slab is a LINTEL (door frame above the doorway), not a leaf. The
door's only effective collider at sphere height is the 0.10 m radius
foot cylinder. The directional tests pass because the cylinder blocks,
not the BSP.
User-reported inside-out off-center walkthrough is the sphere walking
AROUND the foot cylinder (sphere reach 0.48 + cyl 0.10 = 0.58 m; any
sphere center over 0.58 m from cylinder center passes freely). The
visual "body partially intersects door" is the character model
occupying the visual door volume while the collision sphere passes
beside the cylinder.
Reframed handoff in docs/research/2026-05-25-door-bug-partial-fix-shipped.md
points to three candidate next-step investigations:
- Retail-faithfulness audit on setup.Radius / setup.Height interpretation
- Re-inspect door parts 1+2 (GfxObj 0x010044B6) for missed physics shapes
- Test the cottage cell BSP (cell 0x0150 walls) + door together — the
COMBINED collision may be what retail relies on
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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