The autonomous visual loop on the stateful-sought camera exposed the true
root of the #176 stripes: a ~19Hz SAWTOOTH. The sought re-extends ~3mm/frame
and the sweep silently passes while the 0.3m viewer sphere presses up to
~0.25m past the wall plane, then clips a whole transition step (~0.27m) back.
Headless replay against the real Facility Hub corridor BSP (0x8A020164, the
captured ray) reproduced it exactly: pre-fix, embedded targets passed
unclipped and the first detection stopped at the PREVIOUS STEP BOUNDARY,
tracking the target (eyeBack = s - 0.27).
Root cause: BSPQuery.AdjustToPlane - copied from ACE's BSPTree.cs port -
was structurally inverted and ALWAYS returned false (the touchTime==1 branch
re-placed the sphere at the unchanged check position; touchTime<1 iterated
doing nothing; the <0.02 convergence exit returned false). With the
PerfectClip exact-contact machinery dead, CollideWithPt always fell to the
bare Collided path and the transition reverted the colliding step whole.
ACE never noticed: PERFECT_CLIP (0x40) is a client camera flag the server
never exercises (feedback_bn_decomp_field_names class 3 - the retail binary
outranks ACE in branches ACE never runs). The pre-stateful camera flipped
1-step vs 2-step backoffs on mm drift - the measured pulledIn 0.27 <-> 0.53
of the original #176 strobe was step quantization all along.
Rewritten per the retail binary (pseudocode doc
docs/research/2026-07-06-adjust-to-plane-pseudocode.md):
- BSPTREE::adjust_to_plane (0x00539bf0): clearTime/hitTime bounds (0.0/1.0),
Phase 1 walks plane-touch times re-testing the whole tree (the tree test
feeds a DIFFERENT blocking poly back into the next iteration), Phase 2
binary-searches with the SHARED iteration counter, window < 0.02 =
CONVERGED, final commit = last known-clear time. Only failure = Phase-1
exhaustion.
- CPolygon::adjust_sphere_to_poly (0x00538170): early-out = plane-band test
at the START position (was: precise-poly test at the check position);
touch side = sign(dpPos)*radius (was: hard-coded -radius; ACE misdecoded
it as movement.LengthSquared() <= r^2); result unclamped per retail.
Replay pin Issue180CorridorSweepHysteresisReplayTests: short-of-touch
targets pass, past-touch targets always clip, and the clipped stop is the
CONSTANT surface-contact point (eyeBack 1.609 across the band; spread
< 0.03m) instead of tracking the target.
Suites green (Core 2600+2skip / App 729+2skip / UI 425 / Net 385).
Pending: visual-loop re-verify + the user gate (#180 + #176 re-gate).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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