Parallel Volume Rendering Unstructured Data: A Distributed Approach

The development of effective parallel rendering algorithms for unstructured volume data is challenging due to the irregular and adaptive nature of the corresponding meshes. Most of the algorithms developed previously have been mainly for shared-memory architectures. Only a distributed approach can better meet the computational and memory requirements of the rendering calculations. This paper presents a volume rendering algorithm that distributes both the data and the rendering process among the processors. At each processor, ray-casting of local data is performed independent of the other processors. The global image compositing processes, which require inter-processor communication, are overlapped with the local ray-casting processes to achieve better parallel efficiency. In theory, this algorithm should attain high parallel efficiency but its implementation on the Intel Paragon shows otherwise. Besides the added ray-casting overhead, a critical factor is the imbalanced load due to the..