Root cause (b): ShadowObjectRegistry.GetNearbyObjects (line 480) returns early
when primaryCellId is an indoor cell, skipping the outdoor radial sweep that
contains the landblock-baked cottage exterior-shell GfxObj. The issue-#98 fix
that prevents the player's head sphere from being capped by the cottage floor
also prevents the IsViewer camera sweep from finding the exterior building shell.
Result: camera passes through exterior walls unimpeded, driving the residual
transparent-walls symptom after the U.4c flap fix.
Evidence: live capture shows eyeInRoot=n ~90% of frames, eye-player distance
3.43m (full chase, no pull-in). RED test deterministically reproduces: synthetic
indoor cell (0xA9B40175) + exterior GfxObj registered at cellScope=0; probe
SweepEye returns pulledIn=0.0000m (full eye distance Y=5.0, wall at Y=4.0).
Fix design: exempt IsViewer from the indoor-primary early-return gate in
GetNearbyObjects — retail's find_obj_collisions (named-retail :308918) has no
indoor/outdoor cell gate; the acdream fix is correct only for IsPlayer.
Apparatus committed:
- tests/AcDream.App.Tests/Rendering/CameraCollisionIndoorTests.cs (RED test)
- docs/research/2026-05-31-camera-collision-indoor-diagnosis.md (findings + design)
- PhysicsCameraCollisionProbe.cs [flap-sweep] diagnostic retained (U.4c spike)
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>