Comparison of some ray generators for ray tracing volumetric data

Ray tracing is a popular technique for rendering not only analytical objects, but also volumetric data, either synthetized or measured. Different techniques for the ray definition by traversal of the voxel space were designed. The first part of the paper is an overview of ray tracing or ray casting algorithms for the volume data. Stress is laid upon exploiting various kinds of speed up techniques. In the second part, we compare some of these approaches in a computer experiment. Further we show that an appropriate choice of background traversal algorithm can significantly shorten computation time of the exact ray-surface intersection point