Authors: Junpeng Wang, Fei Yang, Yong Cao
Abstract: Most of the GPU-based ray casting algorithms map volume data to 3D texture of the GPU, so that the hardware-accelerated tri-linear interpolation could be taken advantage of. However, in hardware, texture cache is implemented in a 2D fashion. As a result, the viewing direction has a significant effect on the texture cache hit rate. This paper presents a new sampling strategy, i.e. warp marching, for the ray casting algorithm. The new strategy samples volume data in a cache-friendly manner and displays a novel computation-to-core mapping. We apply it to the existing iso-surface volume rendering algorithm and demonstrate significant performance enhancements in certain viewing directions.