A High-Resolution Compression Scheme for Ray Tracing Subdivision Surfaces with Displacement

Subdivision surfaces, especially with displacement, are one of the key modeling primitives used in high-quality rendering environments, such as, e.g., movie production. While their use easily maps to rasterization-based frameworks, they pose a significant challenge for ray tracing environments. This is due to the fact that incoherent access patterns require storing or caching fully tessellated and displaced meshes for efficient intersection computations. In this paper we use a two-tier hierarchy built on a scene's patches. It relies on compressed and quantized bounding volumes on the second tier to reduce the size of the BVH itself. Based on this acceleration structure, we propose a quantized, compact approximation for leaf nodes while being faithful to the underlying patch-geometry. We build on recent advances and present a system that shows competitive performance regarding run-time speed, which is close to full-resolution pre-tessellation methods as well as to previous compression approaches. Ultimately, we provide strong compression of up to a factor of 5: 1 compared to state-of-the-art methods while maintaining high geometrical fidelity surpassing similarly compact approximations and getting close to uncompressed geometry.