Efficient volume rendering using octree space subdivision
Peter Krumhauer, Michael Tsygankov, Christian Reich, Anton Evgrafov · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1999
This paper describes a discrete ray-tracing algorithm, which employs the adaptive hierarchical spatial subdivision (octree) technique for 3D uniform binary voxel space representation. The binary voxel space contains voxels of two kinds: 'surface' and 'non-surface.' Surface voxels include property information like the surface normal and color. The usage of octrees dramatically reduces the memory amount required to store 3D models. The average compression ratio is in the range between 1:24 up to 1:50 compared to uncompressed voxels. A fast ray casting algorithm called BOXER was developed, which allows rendering 256 X 256 X 256 and 512 X 512 X 512 volumes nearly in real-time on standard Intel-based PCs.