Fast and Accurate Ray-Voxel Intersection Techniques for Iso-Surface Ray Tracing

A new intersection algorithm for iso-surface volume ray tracing increases performance by roughly a factor of three compared to previous accurate intersection algorithms while offering similar perfor- mance as previous algorithms that only approximated the solution. The image shows some of the test data sets: Bonsai tree, aneurism, engine, and skull. Abstract Visualizing iso-surfaces of volumetric data sets is becoming increasingly important for many practi- cal applications. One crucial task in iso-surface ray tracing is to find the correct intersection of a ray with the trilinear-interpolated implicit surface de- fined by the data values at the vertices of a given voxel. Currently available solutions are either accu- rate but slow or they provide fast but only approxi- mate solutions. In this paper, we analyze the available techniques and present a new intersection algorithm. We com- pare and evaluate the new algorithm against previ- ous approaches using both synthetic test cases and real world data sets. The new algorithm is roughly three times faster but provides the same image quality and better nu- merical stability as previous accurate solutions.