Five pillars, four colored point lights; closest-hit emits one shadow ray
per light from the same invocation (raysPerPixel = 4, maxDepth = 2), so up
to four rays per pixel rtAccumulate in a single SHADE pass — the contention
case #30 exists for. Each pillar casts four separable colored shadows; an
accumulator race or capacity drop shows as flickering dark noise or a
missing shadow color. Two frames a second apart diff at 2 px / 1.85 M
(last-ulp CAS ordering), confirming no lost updates.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
RT→rgba16float→threshold→blur→composite, end-to-end proof of the three
primitives. threshold/blur run from onBeforeUpdate (one submit each) so the
storage-write→sampled-read dependency gets WebGPU's per-submit barrier
(there is none between dispatches within a compute pass); the composite is a
UI custom shader so it owns the canvas ping-pong. Documents the Vulkan
symmetry (gap 4): the native present path records passes generically and
barriers between them, so the same chain is wireable today.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds an 8^3 = 512-instance TLAS pick test that shoots one analytically
determined ray through a rayQuery=true PlainComputeShader and checks the
read-back committed hit (customIndex 484, t 40.75). 512 instances sit in
the < 8193 regime that the hardcoded 16384-leaf start used to miss, so the
example fails fast if the shim regresses. Verified in Firefox/WebGPU:
"[RayQueryPick] PASS".
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
