opacity micromaps

Opacity Micromaps (OMMs) are a feature introduced alongside Shader Execution Reordering (SER) in DirectX Raytracing (DXR) 1.2, part of Shader Model 6.9 and the DirectX Agility SDK 1.619 from Microsoft. OMMs help reduce performance bottlenecks in heavy ray tracing and path tracing workloads by efficiently handling alpha-tested geometry, such as foliage or fences, which traditionally cause costly shader divergence. By encoding opacity information at a fine granularity, OMMs allow the ray tracing pipeline to skip unnecessary intersection tests and shader invocations. This technology is designed to improve frame rates in games and applications that rely on complex ray tracing effects, complementing SER to deliver smoother performance on compatible GPUs.