Segmented ray casting data parallel volume rendering

Volumetric data are rendered onto an image plane by first organizing the volumetric data into a plurality of blocks of data, each block of data including a plurality of voxels arranged in cubic structure. The blocks of volumetric data are stored in, and processed by a processor element array of a massively data-parallel computer system. For any viewing angle, a plurality of parallel rays are cast through the image plane to traverse the volumetric data. In a ray collection phase, each processor element, in parallel with the other processor elements, determines which segments of the rays interpolate voxels of its associated block of data. In a segment value combination phase, each processor element, in parallel with the other processor elements, determines the integrated contribution of the interpolated voxels on the path of the ray segments traversing its block of data. And, in a final accumulation phase, the segment values for each ray are accumulated in order to determine the value of the pixels associated with each of the ray segments.