AMD details tetrahedral cage ray tracing to cut VRAM usage

AMD published research on a tetrahedral cage ray tracing technique that animates only an outer cage while keeping dense geometry and its BVH static. On a Radeon RX 9070 XT, a scene with roughly 500 million ray-traced triangles ran above 60FPS at 1080p, with acceleration structure updates dropping from over 300ms to 3.3ms and memory falling from up to 80GB to about 1.7GB.

• Scene: 25,000 foliage items and about 500 million ray-traced triangles per frame
• Acceleration structure updates: 3.3ms versus over 300ms with conventional BVH
• Acceleration structure memory dropped from up to 80GB to around 1.7GB
• Best suited to foliage, grass and crowds rather than fine mesh deformation