We present an algorithm that accelerates the extraction of iso-surfaces from unstructured grids by avoiding the traversal of the entire set of cells in the volume. The algorithm consists of a sweep algorithm and a data decomposition scheme. The sweep algorithm incrementally locates intersected elements and the data decomposition scheme restricts the algorithm's worstcase performance. For data sets consisting of hundreds of thousands of elements, our algorithm can reduce the cell traversal time more than 90% over the naive isosurface extraction algorithm, thus facilitating interactive probing of scalar elds for large-scale problems on unstructured three-dimensional grids.
Han-Wei Shen, Christopher R. Johnson