Wire the BFS visibility root to DataCache.CellGraph.CurrCell (the physics
membership answer written in W2 Task 1) rather than resolving independently
from a position via FindCameraCell. Closes the render/physics disagreement
that causes the "world from below" spawn-in flicker.
Changes:
- CellVisibility.GetVisibleCells: extracted BFS body into new private
GetVisibleCellsFromRoot(LoadedCell root, Vector3 cameraPos); existing
GetVisibleCells delegates to it after FindCameraCell (behavior unchanged).
- CellVisibility.ComputeVisibilityFromRoot(LoadedCell? root, Vector3 fallbackPos):
new public entry point; when root is null falls through to ComputeVisibility
(exact today's behavior), otherwise sets _lastCameraCell = root and delegates
to GetVisibleCellsFromRoot — cannot regress below baseline.
- GameWindow (line 7156): replaced ComputeVisibility(visRootPos) with
ComputeVisibilityFromRoot(physicsRoot, visRootPos) where physicsRoot is
resolved from _physicsEngine.DataCache.CellGraph.CurrCell via TryGetCell.
physicsRoot is null whenever CurrCell is null or its id is not yet in the
render registry, so the fallback fires until the cell loads.
- 6 new tests in CellVisibilityFromRootTests: null-root fallback equivalence
(3 cases), registered root → CameraCell == root (3 cases). All 160 App.Tests
pass, 0 regressions.
Visual verification PENDING — behavior change; do not claim it works visually.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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