Vertex-blend attribute compression

Abstract

Skeleton-based animations require per-vertex attributes called vertex-blend attributes. They consist of a weight tuple and a bone index tuple. With meshes becoming more complex, vertex-blend attributes call for compression. However, no technique exists that exploits their special properties. To this end, we propose a novel and optimal weight compression method called Optimal Simplex Sampling and a novel bone index compression. For our test models, we compress bone index tuples between 2.3:1 and 3.5:1 and weight tuples between 1.6:1 and 2.5:1 while being visually lossless. We show that our representations can speed rendering and reduces GPU memory requirements over uncompressed representations with a similar error. Further, our representations compress well with general-purpose codecs making them suitable for offline-storage and streaming.