A divided-screenwise hierarchical compositing for sort-last parallel volume rendering

In this work, to render at least 5123 voxel volumes in real-time, we have developed a sort-last parallel volume rendering method for distributed memory multiprocessors. Our sort-last method consists of two methods, Hsu’s seg-mented ray casting and our divided-screenwise hierarchi-cal (DSH) compositing, in which each processor produces a subimage and merges all the produced subimages into the final image. This paper describes the DSH method, which aims at achieving high performance compositing on a large number of processors. Our implementation on a 64-node PC cluster can composite a 5122 pixel image about twice as fast as an existing method, the binary-swap method, so that can render a 512x512x224 voxel volume at approxi-mately eight frames per second (fps). 1