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*    GRAND Seminar
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*    http://cs.gmu.edu/~robotics/pmwiki.php/Main/GrandSeminar
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*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.


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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