oriented-bbox-not-set-on-rdna4

Status: shipped (Phase 8) — see CHANGELOG.

What it detects

A defensive informational rule. Fires once per source that contains any RT call (TraceRay, RayQuery::Proceed, TraceRayInline) under the [experimental.target = rdna4] config gate.

Why it matters on a GPU

Per Chips and Cheese's RDNA 4 raytracing deep-dive, RDNA 4 gains up to 10% RT performance when the BLAS is built with the D3D12_RAYTRACING_GEOMETRY_FLAG_USE_ORIENTED_BOUNDING_BOX (or VK equivalent) flag. The flag is project-side state -- we cannot inspect it from shader source -- so the rule emits a one-time-per-source informational note pointing the developer to verify their BLAS-build code.

Options

none. Activated only under [experimental] target = "rdna4".

Fix availability

none — Project-side configuration cannot be inspected from shader.

See also

• Chips and Cheese: RDNA 4 raytracing improvements