Advanced Illumination Techniques for GPU Volume Raycasting

Abstract

GPU-based ray-casting techniques are becoming more and more important for the visualization of volume data in medicine and engineering. Thanks to their flexibility and accuracy, they will likely replace existing slice-based techniques in the near future. This tutorial targets the growing number of developers and scientific researchers who work with specialized volume visualization algorithms on state-of-the-art graphics hardware. Starting with a brief introduction to the concepts behind GPUbased ray-casting, we will review existing techniques capable to accelerate the rendering performance. These acceleration techniques are the key issue for supporting advanced illumination models, since these models usually consume more rendering time. In contrast to commonly used local illumination models, advanced illumination models allow to incorporate the light interactions between neighboring structures. Such effects include soft and hard shadows as well as translucency and multiple scattering. The tutorial focuses strongly upon those effects, which support improved spatial comprehension and are thus relevant for scientific visualization from a perceptual point of view, but it also covers topics more related to visual arts.