Ray Casting of Multiple Multi-Resolution Volume Datasets

We developed a GPU-based volume ray casting system for rendering multiple arbitrarily overlapping multi-resolution volume data sets. Our efficient volume virtualization scheme is based on shared resource management, which can simultaneously deal with a large number of multi-gigabyte volumes. BSP volume decomposition of the bounding boxes of the cube-shaped volumes is used to identify the overlapping and non-overlapping volume regions. The resulting volume fragments are extracted from the BSP tree in front-to-back order for rendering. The BSP tree needs to be updated only if individual volumes are moved, which is a significant advantage over costly depth peeling procedures or approaches that use sorting on the octree brick level.