AMD showed off a new ray tracing technology that looks particularly interesting in the context of the eternal discussion about video memory shortages. The company’s researchers were able to instantly track approximately 500 million animated triangles at over 60 FPS at 1080p resolution on the Radeon RX 9070 XT.
The secret lies in the so-called tetrahedral shell. Rather than recalculating large amounts of geometry and corresponding BVH structures every frame, AMD places complex models within simpler deformable shells. And the geometry itself and its BVH remain static and can be reused.
The difference is impressive. In a demo containing approximately 25,000 individually animated plants, the traditional approach required up to 80 GB of memory for BVH alone and took more than 300 milliseconds to update each frame. The new technology took about 1.7 GB and 3.3 milliseconds respectively. In other words, the memory required is reduced by almost 47 times, and the update speed is increased by more than 90 times.
Indeed, there is no magic here. This method works best for vegetation, grass, crowds, and other objects that don’t require fully precise deformation of every vertex. Complex character animation and topology changes have their limits.