Interactive Iso-Surface Ray Tracing of Massive Volumetric Data Sets

Heiko Friedrich, Ingo Wald, Johannes Günther, Gerd Marmitt, and Philipp Slusallek
Proceedings of the 2007 Eurographics Symposium on Parallel Graphics and Visualization, pp. 109-116
Lugano, Switzerland, May 20th-21th, 2007



The visualization of iso-surfaces from gridded volume data is an important tool in many scientific applications. Today, it is possible to ray trace high-quality iso-surfaces at interactive frame rates even on commodity PCs.However, current algorithms fail if the data set exceeds a certain size either because they are not designed for out-of-core data sets or the loading times are too high because there is too much overhead involved in the out-of-core (OOC) techniques. We propose a kD-tree based OOC data structure that allows to ray trace iso-surfaces of large volumetric data sets of many giga bytes at interactive frame rates on a single PC. A LOD technique is used to bridge loading times of data that is fetched asynchronously in the  background. Using this framework we are able to ray trace iso-surfaces between 2 and 4 fps on a single dual-core Opteron PC at 640×480 resolution and an in-core memory footprint that is only a fraction of the entire data size.