Apparatus + handoff for the indoor flap. Confirmed (primary evidence): the flap is the
portal-flood clip being µm-sensitive at the threshold, driven by a ~1-8µm jitter in the
player RenderPosition (physics resting position not bit-stable; Lerp surfaces it). REFUTES
the 2026-06-07 see-through/EnvCell/outdoor-node diagnosis (ModelId GfxObj 0x01000A2B IS the
solid exterior) AND an enqueue-once attempt (retail propagates late slices via AddToCell;
the existing PropagatesNewSlicesToExit test caught it; reverted). Adds: Build determinism
test, A8CellAudit gfxobj dump, [pv-input] 6dp probe + [render-sig] outRoot/bshell fields.
No functional fix shipped. Next: higher-precision physics rest trace -> port retail
kill_velocity/contact rest-stability. Canonical: docs/research/2026-06-08-flap-rootcause-physics-rest-handoff.md
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Per senior-eng direction: the retail-faithful fix is to stop diverging from PView::
AddViewToPortals (first-discovery enqueue + AddToCell/FixCellList in-place growth, no
re-enqueue/re-clip), removing acdream's MaxReprocessPerCell re-enqueue fixpoint and its
documented per-round ProjectToClip drift. Drops the overlap-predicate approach. Viewpoint
bit-stability (the ~1-8um player RenderPosition jitter) is the contingency next step only
if a residual flap survives the visual gate.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Confirmed root cause via primary evidence (determinism test + 6dp jitter probe + retail
grounding): the flap is portal-flood set-membership flipping because the drift-prone
ClipToRegion vertex count gates membership while the player RenderPosition micro-jitters
(~1-8um) into a grazing portal's knife-edge clip. Design: gate membership on a stable
side-test + view-region overlap, not the vertex count. Refutes the 2026-06-07 see-through/
EnvCell/outdoor-node handoff (ModelId GfxObj 0x01000A2B is the solid exterior; outside is
stable; root is stable 0170).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
