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

Abstract

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 performance as previous algorithms that only approximated the solution. The image shows some of the test data sets: Bonsai tree, aneurism, engine, and skull. Visualizing iso-surfaces of volumetric data sets is becoming increasingly important for many practical applications. One crucial task in iso-surface ray tracing is to find the correct intersection of a ray with the trilinear-interpolated implicit surface defined by the data values at the vertices of a given voxel. Currently available solutions are either accurate but slow or they provide fast but only approximate solutions. In this paper, we analyze the available techniques and present a new intersection algorithm. We compare and evaluate the new algorithm against previous 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 numerical stability as previous accurate solutions. 1