Cross-Node Occlusion in Sort-Last Volume Rendering

Abstract

In the field of parallel volume rendering, occlusion is a concept which is already widely exploited in order to improve performance. However, when one moves to larger datasets the use of parallelism becomes a necessity, and in that context, exploiting occlusion to speed up volume rendering is not straightforward. In this paper, we propose and detail a new scheme in which the processors exchange occlusion information so as to speed up the rendering by discarding invisible areas. Our pipeline uses full floating point accuracy for all the intermediate stages, allowing the production of high quality pictures.We further show comprehensive performance results using this pipeline with multiple datasets and demonstrate that cross-processor occlusion can improve the performance of parallel volume rendering.