omm-traceray-force-omm-2state-without-pipeline-flag
Status: stub. The full-length analysis is queued for a v1.0.x patch release per ADR 0018, section 5, criterion #6. The companion rule page at docs/rules/omm-traceray-force-omm-2state-without-pipeline-flag.md contains the canonical detection logic + GPU reasoning.
TL;DR
The DXR 1.2 OMM specification has a project-level gate (D3D12_RAYTRACING_PIPELINE_FLAG_ALLOW_OPACITY_MICROMAPS) and a per-trace gate (the ray flag of the same name). Both must be set for OMM consultation to happen on a given trace. The pipeline flag is set in the state-object's pipeline-config subobject and reflects the application's promise to the runtime that OMM blocks may be present in the BVH; the per-trace flag is the request.
What the rule fires on
A TraceRay(...) call with RAY_FLAG_FORCE_OMM_2_STATE set when the DXR pipeline subobject's D3D12_RAYTRACING_PIPELINE_FLAG_ALLOW_OPACITY_MICROMAPS is not set. The rule reads the pipeline-flags subobject through Slang reflection and compares it against the constant-folded ray flags at the trace site; mismatch fires.
See the What it detects section of the rule page for the full pattern definition.
Why it matters
The full GPU-mechanism analysis lives in the Why it matters on a GPU section of the companion rule page.
Examples
The bad / good code snippets are kept canonical on the rule page; see omm-traceray-force-omm-2state-without-pipeline-flag.md -> Examples.
See also
- Rule page -- canonical reference + change log.
- opacity-micromaps overview -- broader context.
- ADR 0018 -- v1.0 readiness plan.
This is a v1.0-ship stub. Full analysis pending; track issue link TBD.