Parallel Volume Rendering with Early Ray Termination for Visualizing Large-Scale Datasets

This paper presents an efficient parallel algorithm for volume rendering of large-scale datasets. Our algorithm focuses on an optimization technique, namely early ray termination (ERT), which aims to reduce the amount of computation by avoiding enumeration of invisible voxels in the visualizing volume. The novelty of the algorithm is that it incorporates this technique into a distributed volume rendering system with global reduction of the computational amount. The algorithm also is capable of statically balancing the processor workloads. The experimental results show that our algorithm with global ERT further achieves the maximum reduction of 33% compared to an earlier algorithm with local ERT. As a result, our load-balanced algorithm reduces the execution time to at least 66%, not only for dense objects but also for transparent objects.