Visual verification of A6.P7 at Holtburg cottage door passed cleanly
(1187 [cyl-skip-bsp] guard fires, 0 [cyl-test] on doors, 30/30
axis-aligned hits, smooth NE/SE slide along door face). While
exploring post-verification, the user discovered a different
staircase in cells 0xA9B40159 + 0xA9B4015A where the sphere cannot
climb at all.
Captured working baseline (stairs-working.jsonl, cottage cellar
stairs in cells 0xA9B40143/146/147 — clean ↔ Z=90.95-94.00 traversal)
and broken scenario (stairs-broken.jsonl, Z stays at 94.00 the entire
4216-record capture).
Root cause is NOT a regression of A6.P7. It's a different bug shape:
the staircase is built as a multi-part EnvCell entity (entityId
0x0040B500, ~150 parts), with 10 of those parts being 0.80m-radius
cylinders forming the steps. Each cyl carries state=0x00000000 — no
HAS_PHYSICS_BSP_PS — so A6.P7's BspOnlyDispatch guard correctly
doesn't fire. Cyl height 0.80m exceeds A6.P6's step-up budget 0.60m
so grounded step-over fails. Falls through to wall-slide which
produces the same diagonal radial phantom A6.P7 closed for the door.
The [resolve-bldg] lines reveal gfxObj=0x0100081A hasPhys=False
bspR=0.00 vAabbR=0.82 — the underlying GfxObj has NO physics BSP;
we appear to be synthesizing a cyl from the visual AABB radius. That
synthesis path is the suspected misregistration.
Filed as issue #101 with severity HIGH. Investigation handoff written
covering 4 retail-research questions (cdb on retail at this stair
location, Setup trace via entity-source probe, ShadowShapeBuilder
vAabbR fallback audit, cell BSP poly dump), do-not-retry list, and 3
candidate fix shapes (don't synthesize cyl from vAabbR / cell BSP for
stairs / cyl-height-tolerant step-over). The handoff explicitly
defers implementation to a later session pending retail evidence.
Files:
- docs/research/2026-05-25-stairs-cyl-investigation-handoff.md (new)
- docs/ISSUES.md — added #101 entry
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
8795655250