Topologically Clean Isosurface Extraction

This real-time video shows the computation of the Reeb graph on the standard "Post" data-set, a simulation of liquid oxygen diffusion. Since the volumetric mesh has an handle in the center, previous visualization techniques based on Contour trees could not apply before. In this example, we extend topologically clean isosurface extraction (a classical application of the Contour tree in visualization) to volumetric meshes with handles. First, several isosurfaces are extracted using fast seed set extraction from the Reeb graph. Then, thanks to a simplification algorithm inspired from persistent homology,the Reeb graph is progressively simplified. As a consequence, small contours are progressively removed, by order of geometrical importance, and the main components of the isosurfaces are progressively highlighted. Finally, interactive topologically clean isosurface exploration is shown by sweeping in real-time the isosurfaces of the field.