Slice 2 v1 (`892019b`) attempted to close issue #96 by removing the
PhysicsEngine.cs L622 per-tick CP seed. v1 build/test green, CP-write
count dropped 91% in scen3 re-capture, BUT user happy-test surfaced
a regression: BSP step_up at the last step of stairs failed because
sub-step 1's AdjustOffset had no ContactPlane to compute the lift
direction.
Slice 2 v2 (`f8d669b`) reverted the seed removal + added a no-op-if-
unchanged guard inside CollisionInfo.SetContactPlane. The guard
early-returns when called with values matching current ci state.
Outcome:
- #96 PARTIALLY ADDRESSED, scope updated in ISSUES.md to "accepted as
documented retail divergence." The seed is load-bearing for step_up;
closing #96 fully would require deeper refactor (AdjustOffset
fallback to body.ContactPlane). Guard is benign improvement.
- Slice 2 v2 verification capture (scen3_inn_2nd_floor_slice2v2/
acdream.log) committed as evidence — 226,464 cp-writes from L624
seed confirms guard doesn't trigger for fresh-ci-per-tick pattern.
- Slice 2 v1 verification capture (scen3_inn_2nd_floor_slice2/
acdream.log) also committed — confirms v1 actually reduced cp-writes
(2,690 total) but the step_up regression made it unshippable.
NEW M1.5 BLOCKER FILED — issue #98: cellar ascent stuck at last step.
Evidence in slice2v2 capture's cell-transit chain:
0xA9B4014B → 0xA9B4014A → 0xA9B4013F → 0xA9B4014A → 0xA9B4014B → ...
(Z stable ~96.4; CellId ping-pongs every tick)
This is Finding 3 family (cell-resolver hysteresis missing) — same
root cause as #90 workaround + scen4 sling-out. Retail oracle:
CObjCell::find_cell_list Position-variant at
acclient_2013_pseudo_c.txt:308742-308783.
NEXT — A6.P3 slice 3:
- Port retail's cell-array hysteresis into ResolveCellId +
CheckBuildingTransit.
- Closes#98 (cellar-up), possibly #97 (phantom collisions same
instability family), enables #90 workaround removal.
Documents updated:
- ISSUES.md — #96 scope updated, #98 filed
- docs/plans/2026-04-11-roadmap.md — A6.P3 slice 2 marked SHIPPED,
slice 3 scope added
- CLAUDE.md — Currently-working-toward block updated to slice 3
Test suite: 1148 pass + 8 pre-existing fail (baseline maintained).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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