****************************************************************** * * * GRAND Seminar * * http://cs.gmu.edu/~robotics/pmwiki.php/Main/GrandSeminar * * ****************************************************************** *Title* Robust Inside-Outside Segmentation using Generalized Winding Numbers *Time/Venue* July 19, noon, Friday, 2013 ENGR 4201 *Speaker* Alec Jacobson Institute of Visual Computing ETH Zurich *Abstract* Solid shapes in computer graphics are often represented with boundary descriptions, e.g. triangle meshes, but animation, physically-based simulation, and geometry processing are more realistic and accurate when explicit volume representations are available. Tetrahedral meshes which exactly contain (interpolate) the input boundary description are desirable but difficult to construct for a large class of input meshes. Character meshes and CAD models are often composed of many connected components with numerous self-intersections, non-manifold pieces, and open boundaries, precluding existing meshing algorithms. We propose an automatic algorithm handling all of these issues, resulting in a compact discretization of the input’s inner volume. We only require reasonably consistent orientation of the input triangle mesh. By generalizing the winding number for arbitrary triangle meshes, we define a function that is a perfect segmentation for watertight input and is well-behaved otherwise. This function guides a graphcut segmentation of a constrained Delaunay tessellation (CDT), providing a minimal description that meets the boundary exactly and may be fed as input to existing tools to achieve element quality. We highlight our robustness on a number of examples and show applications of solving PDEs, volumetric texturing and elastic simulation. *Bio* Alec Jacobson is recent PhD graduate at ETH Zurich in Switzerland advised by Professor Olga Sorkine. He began his PhD work with her at New York University. Before that he completed a bachelor's degree in Mathematics and Computer Science at New York University, working with Professor Denis Zorin. Alec's research interests are interactive shape modeling, interactive animation tools, 3D input devices and user interfaces, and digital geometry processing. --- Yotam Gingold Assistant Professor Department of Computer Science Volgenau School of Engineering George Mason University Office: ENGR 4427 Email: [log in to unmask] Web: http://cs.gmu.edu/~ygingold/ Phone: 703-993-9196