Round 4 (eec95535) fixed wind but introduced a new lighting bug: the
receiver VERTEX shaders source the sun direction from the shadow block,
not only the shadow visibility term. mesh_atmospheric.vert's
accumulateLights read uShadowLightDirectionAndSource unconditionally for
every directional light; terrain_atmospheric.vert did the same for its
single sun term. Round 4's PublishDisabledReceiverBinding writes
direction (0,0,1) into that block on every shadow-gated-off frame (user
sun-shadow-strength 0 in daylight, indoor/portal cover, night), so every
such frame was lighting outdoor terrain and objects from straight
overhead instead of the authored sun. Publishing the environment's real
direction would not have restored parity either -- the celestial shadow
source direction (sun/moon disc) is not the authored light direction.
F1 (BLOCKER): fixed in the shaders themselves, exact parity with the
plain pipeline. Both receiver verts now branch on the same flag bit
acdreamDirectionalShadowVisibility already reads
((uShadowTextureAndFlags.w & 1u) == 0u) and, when clear, use the EXACT
plain-pipeline expression instead of the shadow block's direction:
-uLights[i].dirAndRange.xyz in mesh_atmospheric.vert (matching
mesh_modern.vert, hoisted out of the light loop as a uniform branch);
-uLights[0].dirAndRange.xyz in terrain_atmospheric.vert (matching
terrain_modern.vert's sunDir/-sunDir form). The (0,0,1) word in the
disabled block stays as the documented normalize()-cannot-NaN guard; its
comment now says so explicitly since it is no longer read as a light
direction when the flag is clear.
F2: RenderPrepared's cascadeCount == 0 return is a third bufferless-
disabled path reachable from a frame that already passed Render's own
two gates (the cascade fitter can still find zero usable cascades) --
publishes the same disabled binding now, via the same
PublishDisabledReceiverBinding helper (re-signatured to take a bare
AtmosphericFrameBufferBinding so all three call sites -- Render's two
early-outs plus this one -- share it).
F3: removed a stray duplicated " -- Closeout and merge" fragment under
the plan's VM7 heading.
F4: corrected the false "the flag bit makes it numerically the plain
lighting sum" claim in the plan's round-4 paragraph and in
WbDrawDispatcher.DirectionalShadowReceivers.cs -- the flag bit alone
only fixed the shadow VISIBILITY term (already correct before round 4);
it took both that AND round 5's light-DIRECTION fallback to actually
match the plain pipeline.
T1: extracted Render's gate prologue (environment evaluate -> two
early-outs -> PublishDisabledReceiverBinding) into internal
EvaluateGateAndPublishDisabledBinding(frame, in input, out environment,
out environmentGateTicks), behaviour-preserving, called by Render before
it touches world/terrain -- the ArgumentNullException.ThrowIfNull(world)/
ThrowIfNull(terrain) calls keep their exact position relative to the
gate. No test in this suite constructs a real WbDrawDispatcher +
TerrainModernRenderer pair (still true), so this extraction is what
makes the gate itself testable; two new tests drive it directly with
PlayerInsideCell: true and with ResidentMaximumReachMeters <=
CameraNearMeters, asserting TryGetCurrentFrameBinding true / IsValidFor
false for both.
T2: proves the actual composition WbDrawDispatcher.PipelinesFor and
TerrainModernRenderer both use -- TryGetCurrentFrameBinding feeding
ShouldSelectReceiverPipeline -- selects the receiver pipeline for the
atmospheric world pass once a disabled binding is published, and still
refuses a non-atmospheric pass name.
T3: shader-source guard (same style as AtmosphericPostProcessGraphTests'
existing shader-text tests) pinning that both receiver verts contain the
flag-gated fallback and reference the same uLights expression the plain
verts use, so a future edit that drops the fallback fails this test
instead of only showing up in a pixel capture.
T4: the (0,0,1) test's doc comment and an inline assertion comment now
say the value is a NaN guard, not a light direction.
Regenerated SPIR-V: mesh_atmospheric.vert and terrain_atmospheric.vert
recompiled to different bytes this time (a real code change, not a
comment); manifest updated to match.
Verify: Release build 0 warnings/0 errors. App hermetic-lane filter
6,054/0 failed. Core.Tests 4,695/0 failed. RenderPackValidator 30/30.
Full hermetic-filtered solution: 15,282/0 failed across 15 projects.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
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