Per-Fragment Image-based Flow Visualization using Interactive Surface Extraction from Unstructured Grids

We present a method for image-based visualization of flow fields on unstructured grids. For interactive exploration of flow data from CFD simulations, we combine GPU-accelerated surface extraction methods and line integral convolution (LIC) in a multi-pass algorithm. In contrast to other highly efficient methods, computation of stream lines is performed directly on the unstructured grid, where in previous methods the flow field had to be confined to the extracted surface. The introduced algorithm is based on three passes: Surface extraction, rendering, and computation of stream lines to perform line integral convolution. Point location, a major performance factor in stream line computation on unstructured grids, can be greatly accelerated by reusing data from the surface extraction pass. This allows us to achieve interactive frame rates on current generation graphics hardware for the post-processing of unstructured CFD datasets.