Ports retail ACRender::polyClipFinish (0x006b6d00, pc:702749) near-eye
semantics into PortalProjection.ProjectToClip - the fundamental fix for
the in-plane portal clip family (climb strobes, tower-top roof/floor
flap while turning; live-corroborated this session: [viewer-diff]
0xAAB30108 strobing 27x mid-climb, whole interior dropping at the top).
Pseudocode: docs/research/2026-06-11-polyclipfinish-w0-clip-pseudocode.md.
Three legs, all decomp-driven:
1. ProjectToClip clips at w >= 0 EXACTLY (was EyePlaneW=1e-4), with
retail's any-negative-w gate. Boundary intersections land at w == 0
(homogeneous directions), so a portal the eye is CROSSING yields the
correct unbounded half-region that the bounded view-region clip cuts
to the screen. A w=0 vertex cannot survive a bounded region clip
into the divide (direction fails some edge of any bounded convex
region); the measure-zero corner case is guarded non-finite->empty.
2. CellView.CanonicalKey keys ALL-COLLINEAR (zero-area) views as their
snapped segment ("L:" + extremes) instead of rejecting them - retail
PROPAGATES degenerate views (ClipPortals decomp:433651-433711
forwards any count!=0 GetClip output, no area gate anywhere), keeping
the cell behind an exactly-in-plane portal in the draw list (cells
draw whole; onward floods die naturally). Rejection dropped the
whole chain for the frame - the parked-eye knife-edge band. Finite
key space unchanged -> dedup + strict-growth convergence intact.
3. The EyeInsidePortalOpening rescue is DELETED (the T2-documented
compensation for the 1e-4 divergence) along with EyeStandingPerpDist
+ PointInPoly2D. Empty clip = no flood, period (retail's rule).
CornerFloodReplay - the gate that REFUTED the previous deletion
attempt - passes WITHOUT the rescue under the W=0 port.
Harness criterion corrected to retail's rules (it codified the rescue):
cells fully BEHIND the camera are not required (all-behind portals clip
empty in retail); monotone area holds per root regime; the two
manufactured exact-on-plane steps assert root-only (boundary root pick
is ambiguous; the in-plane portal there is ~perpendicular to the gaze =
genuinely off-screen). Build_CollapsedInteriorPortalNearEye test
inverted to pin the retail empty-clip rule (it pinned the rescue).
New pins: eye-crossing portal -> w==0 boundary verts + half-region (not
sliver); gaze-along-plane degenerate view accepted + segment-key dedup;
non-finite guard. Replay harnesses (CornerFloodReplay, Issue120,
TowerAscent, HouseExit, Issue127) all green.
Suites: App 246+1skip / Core 1430+2skip / UI 420 / Net 294.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Checkpoint of the unified retail-faithful indoor render. The two-week HANG/grey is fixed and the
interior seals (live-verified by the user). Commits the session render-rewrite foundation together
with the fixes that made it functional.
- HANG fix: PortalVisibilityBuilder.Build portal flood did not terminate (the faithful ProjectToClip
near-side clip drifts per round, defeating the CellView dedup; the BFS had no bound after U.2a removed
MaxReprocessPerCell). Fix = drift-tolerant snapped/canonical CellView.Add dedup (PortalView.cs) plus
restored MaxReprocessPerCell=16 bounded re-enqueue (PortalVisibilityBuilder.cs). Re-enqueue is kept
(load-bearing for late-slice propagation, Build_ViewGrowthAfterDoneCell_PropagatesNewSlicesToExit);
only its count is capped. CellViewDedupTests added.
- Seal (DrawCells Task 2): RetailPViewRenderer.DrawEnvCellShells draws EVERY visible cell via
IndoorDrawPlan.ShellPass (was gated on the ClipFrameAssembler slot filter, leaving slot-less cells grey).
- Look-in FPS: GameWindow exterior look-in candidates limited to the player landblock +-1 (was all ~81
loaded LBs iterated every outdoor frame). No behaviour change (far cells were >48m, already culled).
Remaining dominant issue = the FLAP at transitions: viewer-cell metastability (render roots at the
camera-eye cell, which oscillates outdoor-indoor as the 3rd-person boom drifts across the doorway,
confirmed in render-sig). SEPARATE fix, NOT the DrawCells port. Full handoff + flap fix plan + tracked
follow-ups (#78 terrain, look-in-from-inside, look-in FPS, L-spotlight):
docs/research/2026-06-07-indoor-render-session-handoff.md.
Baselines: build 0 err; App.Tests 210/210; Core.Tests 1331 pass / 4 fail (pre-existing) / 1 skip.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
ProjectToNdc clipped only the eye half-space (w>MinW, a 2026-06-03 workaround) and left the 4 frustum side planes to the 2D ScreenPolygonClip. When the eye is within a portal's near plane, small-w verts explode under the perspective divide (probe saw NDC (10.2,-67.4)); the 2D clip then collapses to empty -> OutsideView empty -> terrain Skip -> the bluish doorway void. Clip the eye plane + 4 side planes (homogeneous Sutherland-Hodgman) before the divide so NDC is bounded to the screen by construction, matching retail GetClip -> polyClipFinish (clip in clip-space before the divide; pc:432344).
Partial: NOT the full flicker fix. The dominant cause (camera boom drift + viewer-cell flip at boundaries + missing w=0 near-plane clip) is identified and deferred to the next session per the handoff. 2 RED->GREEN tests.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The cottage doorway 'void' (dark cell + floating entities while the chase camera looks
through the opening): PortalProjection.ProjectToNdc clipped portals on w+z>=0 — the GL
[-1,1] near-plane test — but acdream's camera builds its projection with D3D-convention
Matrix4x4.CreatePerspectiveFieldOfView and a 1.0 m near plane (RetailChaseCamera). Against
that matrix w+z>=0 discards everything within ~0.5 m of the eye, so when the camera orbits
to ~0.1 m from a doorway portal the near edge is clipped, the far edge projects off-screen
([flap] showed p->0171 D=0.10 proj=4 clip=0 ndc Y=-3.5..-6.6), the room behind is culled
(vis=1) and only the tiny vestibule shell draws -> dark void. Rotating away moved the eye
off the portal -> vis=5 -> room rendered.
Fix: clip against the EYE (w > MinW, MinW=0.05 m), near-INDEPENDENT — a portal you're
standing in still projects (covers the screen) so the cell behind stays visible. We only
use the projected x/y for the visibility clip region, so keeping vertices in front of the
near plane is correct. Matches retail PView::GetClip near-clipping the portal before project.
RED->GREEN regression test (doorway 0.1 m from a near=1.0 eye); 177 App tests green; the
existing straddling ±50 bound still holds.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
