Interactive Volume Rendering of Unstructured Grids with Time-Varying Scalar Fields

Abstract

Interactive visualization of time-varying volume data is essential for many scientific simulations. This is a challenging problem since this data is often large, can be organized in different formats (regular or irregular grids), with variable instances of time (from few hundreds to thousands) and variable domain fields. It is common to consider subsets of this problem, such as time-varying scalar fields (TVSFs) on static structured grids, which are suitable for compression using multi-resolution techniques and can be efficiently rendered using texture-mapping hardware. In this work we propose a rendering system that considers unstructured grids, which do not have the same regular properties crucial to compression and rendering. Our solution uses an encoding mechanism that is tightly coupled with our rendering system. Decompression is performed on the CPU while rendering for the next frame is processed. The rendering system runs entirely on the GPU, with an adaptive time-varying visualization that has a built-in level-of-detail that chooses the most significant aspects of the data.