Controlling GPU-based Volume Rendering using Ray Textures

In this paper we introduce a novel approach to control different rendering parameters of volume ray casting. Since the introduction \nof ray casting implementations on programmable graphics hardware, both performance and flexibility have increased \nand are able to outperform texture-based techniques. In addition, by using rays for computing the volume integral instead of \nproxy geometry one has more control over local settings. Therefore, we employ dependent texture lookups to user editable 2D \ntextures, thus allowing for interactive parameter setting on a per-ray basis, at a negligible performance overhead on modern \ngraphics hardware. By those means we are able to control the volume rendering in a way not possible with proxy-based direct \nvolume rendering and demonstrate some exemplary uses.