ray-flag-force-opaque-with-anyhit

Status: shipped (Phase 8) — see CHANGELOG.

What it detects

A TraceRay(...) call with RAY_FLAG_FORCE_OPAQUE set in a translation unit that also defines a [shader("anyhit")] entry point.

Why it matters on a GPU

RAY_FLAG_FORCE_OPAQUE skips AnyHit invocation. Binding an AnyHit and then forcing opaque is dead code or a logic bug -- the AnyHit shader will never run. On RDNA 4, NVIDIA Ada/Blackwell and Intel Xe2, the AnyHit binding still costs scheduling table slots even when never invoked.

Examples

Bad

[shader("anyhit")] void ah(inout Payload p, in Attribs a) {}
[shader("raygeneration")] void rg() {
    TraceRay(scene, RAY_FLAG_FORCE_OPAQUE, 0xFF, 0, 1, 0, r, p); // ah never fires
}

Options

none

Fix availability

suggestion — Either drop the AnyHit shader from the binding or remove RAY_FLAG_FORCE_OPAQUE from the call.