Microsoft has released one of the most significant updates to its DirectX Raytracing (DXR) since its debut in 2018. The update officially introduces clustered geometry and partitioned top-level acceleration structure (PTLAS).
With clustered geometry, Microsoft envisions scenes where all animated and generated geometry is broken down into simple, reusable clusters of triangles. Typically, scenes repeatedly build large bottom-level acceleration structures, which incur additional compute costs. By using clustered geometry, ray tracing can use the full detailed geometry used for standard rasterization instead of proxies, ensuring that ray-traced shadows and reflections match the currently visible scene.
In open-world games, a top-level acceleration structure (TLAS) can lead to massive VRAM and compute demands. To address this, DXR now introduces PTLAS, allowing ray tracing to focus on changes in a specific region while retaining acceleration-structure data elsewhere. Clustered geometry and PTLAS can be used together or separately, with no limitations. NVIDIA's sample of clustered geometry shows the feature in three stages: default, clusters, and triangles applied.
Benchmarking clustered geometry on the AMD Radeon RX 9070 shows significant FPS improvements and substantial VRAM savings. Frame rates can be up to 66 times higher, though in real games a few percentage points of improvement is generally expected. VRAM consumption has been reduced by nearly 90%. All current-generation hardware supports these features, with day-one support from AMD, Intel, NVIDIA, and Qualcomm for their graphics solutions.
Source: TechPowerUp News · Summarized by HeadlinesBriefing