Crafter.Graphics/examples/RayQueryPick
catbot b645746c8c test(webgpu-rt): RayQueryPick example exercising the rayQuery TLAS shim (#25)
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>
2026-06-04 13:33:04 +00:00
..
closesthit.wgsl test(webgpu-rt): RayQueryPick example exercising the rayQuery TLAS shim (#25) 2026-06-04 13:33:04 +00:00
main.cpp test(webgpu-rt): RayQueryPick example exercising the rayQuery TLAS shim (#25) 2026-06-04 13:33:04 +00:00
miss.wgsl test(webgpu-rt): RayQueryPick example exercising the rayQuery TLAS shim (#25) 2026-06-04 13:33:04 +00:00
project.cpp test(webgpu-rt): RayQueryPick example exercising the rayQuery TLAS shim (#25) 2026-06-04 13:33:04 +00:00
raygen.wgsl test(webgpu-rt): RayQueryPick example exercising the rayQuery TLAS shim (#25) 2026-06-04 13:33:04 +00:00
rayquery_pick.wgsl test(webgpu-rt): RayQueryPick example exercising the rayQuery TLAS shim (#25) 2026-06-04 13:33:04 +00:00
README.md test(webgpu-rt): RayQueryPick example exercising the rayQuery TLAS shim (#25) 2026-06-04 13:33:04 +00:00
resolve.wgsl test(webgpu-rt): RayQueryPick example exercising the rayQuery TLAS shim (#25) 2026-06-04 13:33:04 +00:00

RayQueryPick

Regression test for the WebGPU software ray-query shim (additional/dom-webgpu.js, _rqTraverseTlas).

Builds an 8³ = 512-instance TLAS and shoots one fully-determined ray through a rayQuery=true PlainComputeShader. The committed hit is read back to the host and checked against the analytically-known answer (instance customIndex = 484, t = 40.75). On success the console prints:

[RayQueryPick] result: hit=1 customIndex=484 prim=6 t=40.75
[RayQueryPick] PASS — rayQuery TLAS traversal hit the expected instance

Why 512 instances

The TLAS sweep tree is padded to next_pow2(instanceCount) leaves. The rayQuery shim used to detect BVH leaves with a hardcoded 16384 - 1 leaf start, so for any scene with fewer than 8193 instances no node index ever reached a leaf and every pick missed (issue #25). 512 sits squarely in that broken regime, so this example fails fast if the shim regresses to a static leaf start. The shim now derives the leaf start from a per-build RqTlasMeta.nPadded uniform, matching the megakernel _rtwTraverseTlas.

The scene also renders through the wavefront RT pipeline (same as RTStress) so the run produces a visible frame, but the pass/fail signal is the console line above.

cd examples/RayQueryPick
crafter-build -r --target=wasm32-wasip1

WebGPU/DOM only — the native path uses hardware ray queries.