P2 / M1.5 "blocked at the last step" cellar-lip wedge. This session built a faithful
deterministic reproduction and peeled the cause through six evidence-disproven framings
to one bounded question. NO fix landed — the last layers were each disproven by evidence,
and guessing at the load-bearing collision code is the saga's failure mode.
Apparatus:
- CellarLipWedgeTests.cs + Fixtures/cellar-lip/ (3 real cell dumps + wedge-records.jsonl =
29 captured ACDREAM_CAPTURE_RESOLVE wedge calls). Replays the exact calls + body-before
through the lip-cell engine: all 29 reproduce at 0% advance in <200 ms. Tests are
documents-the-bug / diagnostics (GREEN while the wedge exists).
- TEMP probes ([path5-wall]/[fw-enter]/[find-walkable] in BSPQuery; [neg-poly]/[stepsphereup]/
[stepdown-decide]/CheckOtherCells cn/sn/negHit in TransitionTypes), gated on
ACDREAM_PROBE_INDOOR_BSP, marked STRIP. TransitionTypes neg-poly shortcut has a reverted-fix
comment (slide attempt didn't clear the wedge).
- tools/cdb/retail-*-trace.cdb (retail cdb traces).
Findings (handoff: docs/research/2026-06-04-p2-cellar-lip-flatfloor-cp-handoff.md, see the
"NEXT-SESSION KICKOFF" at top):
- Flat-floor contact plane is retail-faithful (v1 trace, full-file correlation). NOT the bug.
- PosHitsSphere cull sign is retail-faithful (cdb -z verified; the Binary Ninja `test ah,N; jp`
parity-jump reads inverted — caught + reverted a wrong fix from that mis-read).
- Sphere radius correct (0.48 player / 0.30 camera probe).
- Retail connector cell 0xA9B40175 never blocks (CEnvCell::find_collisions trace: 0 Collided/Slid).
- PINNED: during the step-up's step-down, BSPQuery.FindWalkableInternal is never called for cell
0171, so the cottage floor (poly 0x0023, Z=94) is never tested as walkable -> no contact plane
-> step-up fails -> StepUpSlide=Collided -> wedge.
Next: trace FindEnvCollisions -> FindCollisions path dispatch for 0171 during StepDown=true (why
StepSphereDown/find_walkable is skipped), port retail, validate via CellarLipWedgeTests, regress
DoorBugTrajectoryReplayTests + visual gate.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Appends the copy-paste kickoff prompt for the next session: pursue the principled
P1 fix for the cellar-lip cell-resolver ping-pong (demote ResolveCellId / make the
swept curr_cell the per-frame membership authority), NOT a stickiness band-aid.
Captures the evidence, apparatus, retail anchors, do-not list, and test baseline.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Instrumented acdream at the cellar lip (ACDREAM_DUMP_STEPUP=1): step-up WORKS
(518 attempts, 220 SUCCESS landing the candidate on the cottage floor Z=94.0,
matching retail's landings), but the committed CurPos never advances -- every
success is reverted, and [cell-transit] shows ResolveCellId ping-ponging every
tick at the 3-cell junction (0xA9B40175<->0174<->0171, reason=resolver). So the
wedge is a MEMBERSHIP cell-resolution instability reverting a working step-up --
NOT a collision/step-up bug, NOT edge-slide.
Notably this contradicts the master-plan P1 claim that ResolveCellId was demoted
out of the per-frame path: it is STILL driving per-frame cell changes here and is
unstable. Fix direction = the parked, approval-gated (a) ResolveCellId
demotion/stickiness (membership), now justified as a real bug by live evidence.
Collision-side fixes (abbd761 B1, 0935a31 slide_sphere) are correct + kept.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Live retail cdb trace (tools/cdb/cellar-corner-escape.cdb) of the Holtburg
cottage cellar-top corner decodes the ground truth: retail escapes by
step_sphere_up->step_up (196x vs 38 near-misses), transitioning the contact
plane from the ramp (N.z=0.78) onto the flat cottage floor (N.z=1.0, 76
landings). acdream slides at the lip and never makes that ramp->floor
transition -> the intermittent cellar wedge.
So the remaining cellar bug is the #98-core step-up-onto-cottage-floor
(DoStepDown / step_sphere_down / find_walkable), which the shipped B1 (abbd761)
+ slide_sphere (0935a31) fixes got close to but didn't finish. Door still
blocks; generic step-up climbs; cellar went always-stuck -> works-mostly.
Next (handoff doc): instrument acdream's OWN corner path (does step_up fire at
the lip and fail to land on the cottage floor?) before porting the lip-climb --
no guessing (#98 saga rule).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
