RLE accelerated volume splatting algorithm
Jiawan Zhang, Zhigang Sun, Jizhou Sun · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2004
Splatting is a one of the most important object-order volume rendering algorithm. In this paper, a new run length encoding (RLE) accelerated, pre-classification and pre-shade volume splatting algorithm is presented, which enhances the speed of splatting without trading off image quality. This new technique saves rendering time by employing RLE mechanism so that only voxels of interest are processed in splatting. Data structures are defined to fully exploit spatial coherence of volume, including a slice scanline pointer array, a data pointer array, a scanline RLE array and an array storing all data of the non-transparent voxels. And a much fast and accurate sheet buffer splatting method is used in the rendering process, which accelerates the splatting by traversing both the voxel scanline and the image scanline in sheet buffer simultaneously. Experiments practice proves that RLE can efficiently skip over transparent voxels and high speedup can be obtained by using the proposed algorithm. Analysis on speed and memory cost of the algorithm is also conducted. This algorithm may be particularly used in situation where transfer function seldom changes.