Issue No.03 - May/June (2005 vol.11)
Milan Ikits , IEEE
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TVCG.2005.46
Harvesting the power of modern graphics hardware to solve the complex problem of real-time rendering of large unstructured meshes is a major research goal in the volume visualization community. While, for regular grids, texture-based techniques are well-suited for current GPUs, the steps necessary for rendering unstructured meshes are not so easily mapped to current hardware. We propose a novel volume rendering technique that simplifies the CPU-based processing and shifts much of the sorting burden to the GPU, where it can be performed more efficiently. Our hardware-assisted visibility sorting algorithm is a hybrid technique that operates in both object-space and image-space. In object-space, the algorithm performs a partial sort of the 3D primitives in preparation for rasterization. The goal of the partial sort is to create a list of primitives that generate fragments in nearly sorted order. In image-space, the fragment stream is incrementally sorted using a fixed-depth sorting network. In our algorithm, the object-space work is performed by the CPU and the fragment-level sorting is done completely on the GPU. A prototype implementation of the algorithm demonstrates that the fragment-level sorting achieves rendering rates of between one and six million tetrahedral cells per second on an ATI Radeon 9800.
Volume visualization, graphics processors, visibility sorting.
Milan Ikits, Jo?o L.D. Comba, Steven P. Callahan, "Hardware-Assisted Visibility Sorting for Unstructured Volume Rendering", IEEE Transactions on Visualization & Computer Graphics, vol.11, no. 3, pp. 285-295, May/June 2005, doi:10.1109/TVCG.2005.46