Ray tracing massive amounts of animated geometry using tetrahedral cages
a day ago
- The AMD FidelityFX Hybrid Shadows sample combines ray traced shadows and rasterized shadow maps for high quality and performance.
- The paper addresses the scaling problem of animated geometry in ray tracing by introducing tetrahedral cages.
- A low-resolution tetrahedral cage is built around a static mesh; only the cage is animated each frame, while static mini-BLASes are reused.
- This approach decouples animation cost from triangle count, reducing computational and memory overhead significantly.
- The method renders roughly 585 million animated triangles at 60 fps on an AMD Radeon RX 9070 XT at 1080p.
- It is ideal for connectivity-preserving animations such as swaying vegetation, grass, crowds, and distant characters.
- Coarser cages minimize memory and cost; finer cages better approximate the original animation.
- Tetrahedron-cage animations can work alongside DXR partitioned top-level structures and cluster level acceleration structures.
- Future work focuses on improved cage generation, animation quality, and integration with modern ray-tracing pipelines.