W. Advanced techniques for high quality multiresolution volume rendering.pdfVIP

Advanced Techniques for High Quality Multiresolution Volume Rendering S. Guthe and W. Strasser WSI/GRIS, University of Tuebingen Abstract We present several improvements for compression based multi-resolution rendering of very large volume data sets at interactive to real-time frame rates on standard PC hardware. The algorithm accepts scalar or multi-variant data sampled on a regular grid as input. The input data is converted into a compressed hierarchical wavelet representation in a pre-processing step. During ren- dering, the wavelet representation is decompressed on-the-fly and rendered using hardware texture mapping. The level-of-detail used for rendering is adapted to the estimated screen-space error. To increase the rendering performance additional visibility tests, such as empty space skipping and occlusion culling, are applied. Furthermore we discuss how to render the remaining multi-resolution blocks efficiently using modern graphics hardware. Using a prototype implementation of this algorithm we are able to perform a high quality interactive rendering of large data sets on a single off-the-shelf PC. Key words: Viewing algorithms, Data compaction and compression 1. Introduction Visualization of large volumetric data is a very common task in many areas in medicine, computational physics and various other disciplines. An important technique in interactively exploring these data sets is direct volume rendering. Texture mapping hardware can be used to implement this rendering efficiently [3]. Commodity graph- ics hardware is capable to perform this rendering technique in real-time on cheap off-the-shelf PCs [5, 11]. The visualization of large data sets (more that 2563 voxel), however, is still infeasible unless massive parallel hardware is used [1]. Since most conventional texture