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Pierre Alliez |
My main research interests are on topics commonly referred to as Geometry Processing: geometry compression, surface approximation, mesh parameterization, surface remeshing and mesh generation. Initially considered as a subfield of Computer Graphics and Computational Geometry, Geometry Processing has developed over the last years into a whole research community seeking automatic, computerized processing of complex shapes. My overall research goal is to design methods which are both theoretically founded and computationally tractable to render them robust to unprocessed inputs, reliable, and, above all, with real impact on technological applications. Targeting these properties requires a complete rethinking of the geometry pipeline and of its foundational algorithms so that bottlenecks (i.e., parts of the pipeline which are too labor–intensive or too brittle for practitioners) are removed.
I was co-chair of the EUROGRAPHICS Symposium on Geometry Processing 2008 and I am this year program co-chair of Pacific Graphics 2010. I received the Eurographics Young Researcher Award 2005. Most recently I have recently defended my habilitation, and I have been nominated as associate editor of the ACM Transactions on Graphics.
Publications and presentations
- you find here a list of my main publications as well as some presentations.
- click here if you look for a more complete list as well as all publications from the GEOMETRICA group.
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Interleaving Delaunay Refinement and Optimization for Practical Isotropic Tetrahedron Mesh Generation Jane Tournois, Camille Wormser, Pierre Alliez and Mathieu Desbrun ACM Transactions on Graphics (SIGGRAPH), 28(3), 2009. Abstract: We present a practical approach to isotropic tetrahedral meshing of 3D domains bounded by piecewise smooth surfaces. Building upon recent theoretical and practical advances, our algorithm interleaves Delaunay refinement and mesh optimization to generate quality meshes that satisfy a set of user-defined criteria. This interleaving is shown to be more conservative in number of Steiner point insertions than refinement alone, and to produce higher quality meshes than optimization alone. A careful treatment of boundaries and their features is presented, offering a versatile framework for designing smoothly graded tetrahedral meshes. |
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Abstract: Isotropic tetrahedron meshes generated by Delaunay triangulations are known to contain a majority of well-shaped tetrahedra, as well as spurious sliver tetrahedra. As the slivers hamper stability of numerical simulations we aim at removing them while keeping the triangulation Delaunay for simplicity. The solution which explicitly perturbs the slivers through random vertex relocation and Delaunay connectivity update is very effective but slow. In this paper we present a perturbation algorithm which favors deterministic over random perturbation. The added value is an improved efficiency and effectiveness. Our experimental study applies the proposed algorithm to meshes obtained by Delaunay refinement as well as to carefully optimized meshes. |
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Filtering Relocations on a Delaunay Triangulation
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CGAL - The Computational Geometry Algorithms Library Pierre Alliez, Andreas Fabri, Efi Fogel. SIGGRAPH 2008 course notes (pdf) |
Students
- 2009-present: Bertrand Pellenard (PhD on resurfacing)
- 2009: Hugo Feree (ENS Lyon: probing implicit surfaces)
- 2009: Rahul Srinivasan (IIT Bombay: accelerating ODT mesh optimization and sliver removal)
- 2008: Amit Gupta (IIT Bombay: Poisson reconstruction for polygon soups)
- 2008: Saurabh
Chakradeo
(IIT Bombay: Fast intersections and projections for polyhedral surfaces)
- 2007: Ankit Gupta (IIT Bombay: PCA in CGAL and application to normal estimation), now at Stanford
- 2006-present: Jane Tournois (PhD on mesh optimization).
- 2006: Lakulish Antani (IIT Bombay: mesh sizing using additively weighted Voronoi diagrams), now at UNC
- 2004: Abdelkrim Mebarki (master: placement of streamlines)
- 2004: Jérôme Gahide (progressive triangle mesh compression)
- 2003-2007: Marie Samozino (Ph.D.: reconstruction of surfaces from noisy point sets), now Professor in Mathematics
- 2002: Mathieu Monnier (compression of 2D vectorial data)
Teaching
- ENPC
- master IGMMV
- MASTER EPU IFI-VIM
Software
I am an avid user of the CGAL library. I am a CGAL developer as well, by implementing or participating to various projects: placement of streamlines from 2D vector fields, planar parameterization of triangle surface meshes (with Laurent Saboret and Bruno Levy), Principal Component Analysis (with Sylvain Pion), Surface reconstruction (with Laurent Saboret and Gael Guennebaud) and Point Set Processing (with Laurent Saboret and Nader Salman).
Demos for windows running with the CGAL library:
- 2D Voronoi diagram and Lloyd iteration
- A tutorial for CGAL Polyhedron
- Estimating curvature tensors on triangle meshes
- Placement of streamlines
3D models
I contributed to coordinate the AIM@SHAPE repository
Current Projects
Focus K3D (EU FP7 Coordination Action)
ANR GIGA (national project about geometric inference and analysis)
ANR GYROVIZ (national project for reconstructing urban scenes from localized photos and videos)
Past Projects
AIM@SHAPE (EU Network of Excellence)
Activities
2010
- Paper co-chair, Pacific Graphics 2010
- Programme committee,
Shape Modeling International
- Programme committee, ACM Symposium on Solid and Physical Modeling
- Paper committee, Eurographics Symposium on Geometry Processing
2009
- Associate editor of the ACM Transactions on Graphics
- Short paper co-chair,
Eurographics
- Programme committee,
IMA Mathematics of Surfaces XIII conference.
- Programme committee, SIAM/ACM Joint Conference on Geometric
and Physical Modeling
- Paper committee, Eurographics Symposium on Geometry Processing
- Paper committee, Pacific Graphics
- Thesis reviewer: Patrick Labatut (ENS Paris)
- Thesis committee: Jean-Marie Favreau (University of Clermont-Ferrand), Jane Tournois (INRIA Sophia)
2008
- Paper co-chair, Eurographics Symposium on Geometry Processing
- paper committee, EUROGRAPHICS
- paper committee, Pacific Graphics
- paper committee, Shape Modeling International
- paper committee, ACm Symposium on Solid and Physical Modeling
- paper committee, Symposium on 3D Data Processing, Visualization and Transmission
2007
- paper committee, SIGGRAPH
- paper committee, CAD/Graphics
- paper committee, Pacific Graphics
- paper committee, Shape Modeling International
- paper committee, ACM Symposium on Solid and Physical Modeling
- paper committee, Eurographics Symposium on Geometry Processing
2006
- paper committee, Pacific Graphics
- associate editor of the Visual Computer
- part of the french ANR project GEOTOPAL
- thesis reviewer: Martin Marinov (RWTH Aachen)
- paper committee, ACM Symposium on Solid and Physical Modeling
- paper committee, Eurographics Symposium on Geometry Processing
- paper committee, IEEE International Conference on Shape Modeling and Applications
2005
- Video and Multimedia presentation program committee, SOCG 2005
- paper committee, EUROGRAPHICS Symposium on Geometry Processing 2005
- paper committee, EUROGRAPHICS 2005
- paper committee, Pacific Graphics 2005
- thesis reviewer: Christian Rossl (MPII Saarbruck), Raphaele Balter (University of Rennes)
- member of thesis committee:Marie-Claude Frasson (University of Nice), Guillaume Lavoue (University of Lyon), Gabriel Peyre (Ecole Polytechnique)
2004-2006
- ACI GeoComp 2004-2007
- AIM@SHAPE EU Network of Excellence (workpackage leader)
2004
- organizing co-chair, Second Eurographics Symposium on Geometry Processing 2004
- paper committee, Eurographics Symposium on Geometry Processing 2004
- paper committee, Eurographics 2004
- paper committee, Pacific Graphics 2004
- paper committee, Shape Modeling International 2004
- member of thesis committee: Frederic Payan