ParVox-a parallel splatting volume rendering system for distributed visualization

The paper presents a parallel volume rendering system, ParVox, for large volumes of 4D data sets in regular structured grids. A parallel volume rendering API based on the splatting algorithm constitutes the core of the ParVox system. A network interface program takes commands from an X Window based GUI, calls the API to perform the rendering functions, compresses the rendered images and sends them back to the GUI window. The ParVox system is designed for interactive, distributed visualization of large multiple time steps, multiple parameters volume datasets. The parallel splatting algorithm employs both object space decomposition and image space decomposition; an asynchronous image compositing scheme based on the direct send model reduces both the communication overhead and the synchronization overhead. The ParVox system architecture, the parallel algorithm and its implementation on the Cray T3D and the parallel wavelet compression algorithm are discussed extensively. The performance results and some optimization techniques are also presented.