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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 received the Eurographics Young Researcher Award 2005. I was co-chair of the EUROGRAPHICS
Symposium on Geometry Processing 2008
and program co-chair of
Pacific Graphics 2010. I have defended my habilitation in 2009,
and I have been nominated as associate editor of the ACM
Transactions on Graphics in 2010.
I have been awarded in 2011 a Starting Grant from the European Research Council. My proposal is entitled IRON, which stands for "Robust Geometry Processing".
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.
Recent publications and Courses:
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Isotropic 2D Quadrangle Meshing with Size and Orientation Control |
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An Optimal Transport Approach to Robust Reconstruction and Simplification of 2D Shapes Fernando de Goes, David Cohen-Steiner, Pierre Alliez, and Mathieu Desbrun. Symposium on Geometry Processing, 2011. Abstract: We propose a robust 2D shape reconstruction and simplification algorithm which takes as input a defect- laden point set with noise and outliers. We introduce an optimal-transport driven approach where the input point set, considered as a sum of Dirac measures, is approximated by a simplicial complex considered as a sum of uniform measures on 0- and 1-simplices. A fine-to-coarse scheme is devised to construct the resulting simplicial complex through greedy decimation of a Delaunay triangulation of the input point set. Our method performs well on a variety of examples ranging from line drawings to grayscale images, with or without noise, features, and boundaries. |
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Polygon Mesh Processing (see also from amazon) See also slides Mario Botsch, Leif Kobbelt, Mark Pauly, Pierre Alliez and Bruno Levy. AK Peters, ISBN 978-1-56881-426-1, 2010. Abstract: Geometry processing, or mesh processing, is a fast-growing area of research that uses concepts from applied mathematics, computer science, and engineering to design efficient algorithms for the acquisition, reconstruction, analysis, manipulation, simulation, and transmission of complex 3D models. Applications of geometry processing algorithms already cover a wide range of areas from multimedia, entertainment, and classical computer-aided design, to biomedical computing, reverse engineering, and scientific computing. Over the last several years, triangle meshes have become increasingly popular, as irregular triangle meshes have developed into a valuable alternative to traditional spline surfaces. This book discusses the whole geometry processing pipeline based on triangle meshes. The pipeline starts with data input, for example, a model acquired by 3D scanning techniques. This data can then go through processes of error removal, mesh creation, smoothing, conversion, morphing, and more. The authors detail techniques for those processes using triangle meshes. |
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Optimizing Voronoi Diagrams for Polygonal
Finite Element Computations Abstract: We present a 2D mesh improvement technique that optimizes
Voronoi diagrams for their use in polygonal nite element computations.
Starting from a centroidal Voronoi tessellation of the simulation domain we
optimize the mesh by minimizing a carefully designed energy functional that
effectively removes the major reason for numerical instabilities: short edges
in the Voronoi diagram. We evaluate our method on a 2D Poisson problem and
demonstrate that our simple but e ective optimization achieves a significant
improvement of the stiffness matrix condition number. |
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Signing the Unsigned: Robust Surface Reconstruction from Raw Pointsets Patrick Mullen, Fernando de Goes, Mathieu Desbrun, David Cohen-Steiner and Pierre Alliez. EUROGRAPHICS Symposium on Geometry Processing 2010. Abstract: We propose a modular framework for robust 3D reconstruction from unorganized, unoriented, noisy, and outlierridden geometric data. We gain robustness and scalability over previous methods through an unsigned distance approximation to the input data followed by a global stochastic signing of the function. An isosurface reconstruction is finally deduced via a sparse linear solve. We show with experiments on large, raw, geometric datasets that this approach is scalable while robust to noise, outliers, and holes. The modularity of our approach facilitates customization of the pipeline components to exploit specific idiosyncracies of datasets, while the simplicity of each component leads to a straightforward implementation. |
Students and post-docs
- 2012: Manish Mandad (Robust shape approximation with guarantees)
- 2012:
David Bommes (Surface tiling)
- 2011: Simon Giraudot (Robust reconstruction of surfaces)
- 2011: Paul Seron (Reconstruction of urban scenes)
- 2011: Renata Nascimento (visiting PhD student on quadrangle surface tiling)
- 2011: Julie Digne (Robust shape reconstruction)
- 2011: Sagar Chordia (shape approximation)
- 2010:
Alain Tayeb (Meshing NURBS surfaces)
- 2010: Boris Dalstein (quadrangle surface tiling)
- 2009-present: Bertrand Pellenard (PhD on surface and domain tiling)
- 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
- 2006-2009: Jane Tournois (PhD on mesh optimization), now at Vienna university.
- 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
- Ecole des Ponts ParisTech
- 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),
Point Set Processing (with Laurent Saboret and Nader Salman) and 3D Tetrahedron
Mesh Generation (with Mariette Yvinec, Stephane Tayeb, Laurent Rineau and Jane Tournois).
Demos for windows running with the CGAL library:
- 2D Voronoi diagram and Lloyd iteration
- A tutorial for CGAL Polyhedron
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Estimating curvature tensors on triangle meshes
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Placement of streamlines
3D models
I contributed to coordinate the AIM@SHAPE repository
Current Projects
EU Starting grant IRON (Robust Geometry Processing)
ANR GIGA (national project about geometric inference and analysis)
Past Projects
ANR GYROVIZ (national project for reconstructing urban scenes from localized photos and videos)
Focus K3D (EU FP7 Coordination Action)
AIM@SHAPE (EU Network of Excellence)
Activities
2012
- paper committee, EUROGRAPHICS conference (Cagliari, Italy)
- paper committee, Eurographics Symposium on Geometry Processing (Talinn, Estonia)
- program committee,
International Workshop on Point Cloud Processing (in conjunction with CVPR)
- invited speaker, Advances in Architectural Geometry (Paris).
2011
- thesis reviewer: Vincent Vidal (Universite de Lyon)
- habilitation thesis reviewer: Raphaelle Chaine (Universite de Lyon)
- thesis committee: Patrick Mullen (Caltech)
- programme committee, VAST International Symposium on Virtual Reality, Archaeology and Cultural Heritage
- programme committee, Sibgrapi 2011
- paper committee, Eurographics Symposium on Geometry Processing
- programme committee, Shape Modeling International
- thesis reviewer: Clement Courbet (Ecole Centrale Paris)
- thesis committee: Marcio Cabral (INRIA Sophia)
- thesis reviewer: Sahar Hassan (University of Grenoble)
2010
- thesis reviewer: Julie Digne (ENS Cachan)
- 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
- scientific committee: Advances in Architectural Geometry
- thesis committee: Mathieu Bredif (Telecom ParisTech and IGN, France)
- thesis reviewer: Thierry Stein (INRIA Rhone Alpes)
2009
- associate editor of the ACM Transactions on Graphics
- short paper co-chair, Eurographics
- programme committee, IMA Mathematics of Surfaces XIII conference.
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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)
- thesis committee: 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
- thesis reviewer: Christopher Dyken (University of Oslo)
- thesis reviewer: Johan Seland (University of Oslo)
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
- associate editor of Computers & Graphics
- 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