@misc{KaehlerSimonHege, author = {K{\"a}hler, Ralf and Simon, Mark and Hege, Hans-Christian}, title = {Fast Volume Rendering of Sparse High-Resolution Datasets Using Adaptive Mesh Refinement Hierarchies}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-6516}, number = {01-25}, abstract = {In this paper we present an algorithm that accelerates 3D texture-based volume rendering of large and sparse data sets. A hierarchical data structure (known as AMR tree) consisting of nested uniform grids is employed in order to efficiently encode regions of interest. The hierarchies resulting from this kind of space partitioning yield a good balance between the amount of volume to render and the number of texture bricks -- a prerequisite for fast rendering. Comparing our approach to an octree based algorithm we show that our algorithm increases rendering performance significantly for sparse data. A further advantage is that less parameter tuning is necessary.}, language = {en} } @misc{KaehlerHege, author = {K{\"a}hler, Ralf and Hege, Hans-Christian}, title = {Interactive Volume Rendering of Adaptive Mesh Refinement Data}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-6561}, number = {01-30}, abstract = {Many phenomena in nature and engineering happen simultaneously on rather diverse spatial and temporal scales, i.e.\ exhibit a multi-scale character. Therefore various hierarchical data structures and numerical schemes have been devised to represent quantitatively such phenomena. A special numerical multilevel technique, associated with a particular hierarchical data structure, is so-called Adaptive Mesh Refinement (AMR). This scheme achieves locally very high spatial and temporal resolutions. Due to its popularity, many scientists are in need of interactive visualization tools for AMR data. In this article we present a 3D texture-based volume rendering algorithm for AMR data, that directly utilizes the hierarchical structure. Thereby interactive rendering even for large data sets is achieved. In particular the problems of interpolation artifacts, opacity corrections, and texture memory limitations are addressed. The algorithm's value in practice is demonstrated with simulation and image data.}, language = {en} }