Bruno Levy's home page

Latest news

12/7/2023: invited talk. Cycle Sciences et Société: La cosmologie, au carrefour de la physique, des mathématiques et de la physique.
11/6-10/2023: invited talk at CAMS/PIMS mini-school on optimal transport.
10/9-11/2023: invited talk at Tetrahedron VII.
07/18/2023: invited talk at Summer Geometry Initiative: a programmer's adventure into theoretical physics.
07/1-2/2023: invited course: a quick journey into Geometry Processing at Symposium on Geometry Processing grad school
05/22-26/2023: visiting Oxford (cosmo., particle phys. and math. dpts). Working with R. Mohayaee on Monge-Ampère gravitation.
04/06/2023: Exploring the dark side of the Universe (Inria webside) [English] [French]
03/29/2023: Magnum La Radio, les mathétiques permettent de remonter aux origines de l'Univers
03/13-17/2023: co-organized a School of physics in "Les Houches" on Optimal Transport with J.-D. Benamou, Y. Brenier, S. Matarrese, Q. Mérigot and R. Mohayaee
02/22/2023: Our research on cosmology with F. Nikakhtar, R.K. Sheth and R. Mohayaee featured in Yale News
01/17/2023: Notre recherche en cosmologie dans L'Est Républicain et dans la revue de presse de Claude Askolovich sur France Inter.
12/13/2022: Invited talk on Monge-Ampère-Brenier gravity SMAI-SIGMA group
12/02/2022: New article accepted by Physical Review Letters with F. Nikakhtar, R.K. Sheth and R. Mohayaee on Baryon Acoustic Oscillation reconstruction [arXiv]
12/01/2022: Moving from research center director to a national mission on emergent scientific projects and large-scale technological development in the frame of "France-2030" (I will be still hosted in Nancy)
11/17/2022: J'interviens sur France Culture dans "la science, CQFD" [replay] (mon intervention à partir de 23'55'')
10/25/2022: Article on our results on cosmology (with S. von Hausegger et R. Mohayaee) in Chut! Magazine
09/30/2022: Nuit Européenne des Chercheurs [website] [video]
09/02/2022: keynote speaker at IAMG 2022 : "a mathematical time machine" (see below)
05/20/2022: Turning Back Time on Space: our article on Optimal Transport and Baryon Acoustic Oscillations (PRL) featured in Physics J.
02/02/2022: happy to be a RISC-V ambassador

Short Bio

I was born the 14th of May 1972. I defended my Ph.D. in 1999 on computational topology, combinatorics and embedding, directed by Jean-Laurent Mallet. I was awarded the SPECIF prize (now known as Gilles Kahn / Acad. Sci. prize) of the best French Ph.D. thesis in CS, then I did a post-doc in Stanford in 2000. I was hired by Inria in 2000 as a junior researcher. In 2004, I created the ALICE team (it became an Inria project in 2006). I obtained an ERC Starting Grant (GOODSHAPE) in 2008, and an ERC Proof of Concept Grant (VORPALINE) in 2013. I was promoted research director in 2008, 1st class research director (DR1) in 2012 and exceptional class (DR0) in 2021. I was awarded the Inria Young Researcher Award in 2011. In 2019, two new Inria teams stemmed from my previous team ALICE: MFX on compter aided fabrication, and PIXEL on geometry processing.
From Nov. 2018 to Dec. 2022, I was the director of the Inria Nancy Grand-Est research center (450 people, 20 teams, 17 in Nancy, 3 in Strasbourg).

[Archives ALICE 2006-2018]

Research

My initial topic is Geometry Processing. From 1998 to 2006, I focused on the problem of mesh parameterization, and produced several algorithms that became a de-facto standard (LSCM, ABF++, PGP). Then I contributed to two start-up creations, for transferring my results in 3d gridding for oil exploration (Paradigm/Earth Decision Sciences) and visualization (Scalable Graphics)

From 2006 to 2019, I focused on some numerical problems in Scientific Computing. I contributed to lay spectral geometry processing fundamentals and made it practical with the first algorithm that computes a Fourier-like basis for surface meshes (manifold harmonics). I also established the regularity of Lloyd's energy and proposed a Newton solver for quantization, generalized it to propose the first automatic algorithm for hex-dominant meshing (Lp-CVT) and finally the first solver for 3D semi-discrete optimal transport. Most of my research results are available in my GEOGRAM and GRAPHITE Open-Source softwares. The main results of my two ERC projects on meshing and sampling are transferred to Tessael, a start-up we have created.

Now (2020,...) I am mainly working on computational methods for cosmology (Physical Review Letters, 2022) and fluid dynamics (Journal of Computational Physics, 2022). I'm also interested in novel hardware architectures.

Selected Publications

Physics and Optimal transport

Optimal Transport Reconstruction of Baryon Acoustic Oscillations, Farnik Nikakhtar, Ravi K. Sheth, Bruno Lévy and Roya Mohayaee, 2022 (accepted by Physical Review Letters).
Accurate Baryon Acoustic Oscillations reconstruction via semi-discrete optimal transport, Sebastian von Hausegger, B. Lévy and Roya Mohayaee, 2022, Physical Review Letters
Partial Optimal Transport for a Constant-Volume Lagrangian Mesh with Free Boundaries, B. Lévy, 2022, Journal of Computational Physics. [Videos]
A fast semi-discrete optimal transport algorithm for a unique reconstruction of the early Universe , B. Lévy, Roya Mohayaee and Sebastian von Hausegger, 2021, Monthly Notices of the Royal Astronomy Society [arXiv] ,
Notions of optimal transport theory and how to implement them on a computer, B. Lévy and E. Schwindt, 2018, Computer and Graphics J.
Centroidal Power Diagrams, S. Xin, B. Lévy, Z. Chen, L. Chu, Y. Yue, W. Wang , 2016, ACM Trans. on Graphics (SIGGRAPH ASIA)
A numerical algorithm for L2 optimal transport, B. Lévy, 2015, ESAIM Math. Modeling and Analysis (previous version on arXiv)

Sampling and meshing

Restricted Power Diagrams on the GPU , J. Basselin, L. Alonso, N. Ray, D. Sokolov, S. Lefebvre and B. Lévy, 2021, Computer Graphics Forum (Eurographics conf. proc.)
Meshless Voronoi on the GPU, N. Ray, D. Sokolov, S. Lefebvre and B. Lévy, 2018, ACM Transactions on Graphics (SIGASIA conf. proc.)
Computing a high-dimensional euclidean embedding , Z. Zhong, W. Wang, Bruno Lévy, J. Hua, X. Guo, 2018, ACM Trans. on Graphics (SIGGRAPH)
Surface reconstruction by computing restricted Voronoi cells in parallel, D. Boltcheva and B. Lévy, 2017, Computer-Aided design
Anisotropic and feature sensitive triangular remeshing, V. Nivoliers, B. Lévy and C. Geuzaine, 2015, J. of Computational and Applied Math
Revisiting Optimal Delaunay Triangulation, Z. Chen, W. Wang, B. Lévy, L. Liu and F. Sun, 2014, SIAM J. on Sci. Computing
Particle-Based Anisotropic Surface Meshing, Z. Zhong, X. Guo, W. Wang, B. Lévy, F. Sun, Y. Liu and W. Mao, 2013, ACM Trans. on Graphics (SIGGRAPH)
On Centroidal Voronoi Diagrams Y. Liu, W. Wang, B. Lévy, F. Sun, D.-M. Yan, L. Lu and C. Yang, 2009, ACM Trans. on Graphics
Voronoi Parallel Linear Enumeration, B. Lévy and N. Bonneel, 2012, Int. Meshing Roundatble

Hexahedral meshing

Hex-dominant meshing: mind the gap, N. Ray, D. Sokolov, M. Reberol, F. Ledoux, B. Lévy, 2018, Computer-Aided Design
Hexahedral-dominant meshing, D. Sokolov, N. Ray, L. Untereiner, B. Lévy, 2016, ACM Trans. on Graphics
Practical Frame Field Generation, D. Sokolov, N. Ray, B. Lévy, 2016, ACM Trans. on Graphics (SIGGRAPH ASIA)
Dihedral Angle Maps, G.-P. Paillé, N. Ray, P. Poulin, A. Sheffer and B. Lévy, 2015, ACM Trans. on Graphics (SIGGRAPH)
Voronoi Squared Distance Minimization, V. Nivoliers, D.-M. Yan and B. Lévy, 2011, Intl. Meshing Roundtable
Lp centroidal Voronoi Tessellation, B. Lévy and Y. Liu, 2010, ACM Trans. on Graphics (SIGGRAPH) [Recorded talk]
Geometry-aware direction field processing, N. Ray, B. Vallet, L. Alonso and B. Lévy, 2009, ACM Trans. on Graphics
N-Symmetry Direction Field Design, 2008, N. Ray, B. Vallet, W.-C. Liu and B. Lévy, 2008, ACM Trans. on Graphics

Theses

Topologie algorithmique: combinatoire et plongement, B. Lévy, Ph.D. thesis, Oct. 1999, INPL, SPECIF national prize
Géométrie numérique, B. Lévy, Feb. 2008, HdR (habilitation thesis), INPL [English version]

Numerics

A one point integration rule over star convex polytopes, A. Francis, S. Natarajan, E. Atroshchenko, B. Lévy, S. Bordas,
Computers and Structures J, 215, pp 43-64, 2019
Computing the Distance between Two Finite Element Solutions, M. Reberol and B. Lévy, 2018, SIAM J. Sci Computing
The Predicate Construction Kit, B. Lévy, 2015, Computer Aided Design J. (invited talk at IMR 2014)
Spectral Geometry Processing with Manifold Harmonics , B. Vallet and B. Lévy, 2007, Eurographics
Laplace-Beltrami Eigenfunctions, towards an algorithm that "understands" geometry, 2006, Shape Modeling Intl. (invited talk)

Mesh Parameterization (1998-2006)

Periodic Global Parameterization, N. Ray, W.-C. Li, B. Lévy, A. Sheffer and P. Alliez, 2006, ACM Trans. on Graphics
Fast Angle Based Flattening, A. Sheffer, B. Lévy, M. Mogilnitsky and A. Bogomyakov, 2004, ACM Trans. on Graphics
Anisotropic Polygonal Remeshing, P. Alliez, D. Cohen-Steiner, O. Devillers, B. Lévy and M. Desbrun, 2003, (SIGGRAPH)
Dual Domain Extrapolation, B. Lévy, 2003, ACM Trans. on Graphics (SIGGRAPH)
Least Squares Conformal Maps, B. Lévy, S. Petitjean, N. Ray and J. Maillot, 2002, ACM Trans. on Graphics (SIGGRAPH)
Constrained Texture Mapping, B. Lévy, 2001, ACM Trans. on Graphics (SIGGRAPH)
Non-distorted Texture Mapping, B. Lévy and J.-L. Mallet, 1998, ACM SIGGRAPH

Complete list of older publications: (1999-2015). My publications on [google scholar] [DBLP]

Alumni

Sebastian
von Hausegger

Software

GEOGRAM, a library of geometric algorithms.
in-browser demos (using WASM/Emscripten)
GRAPHITE, a 3D modeler (uses GEOGRAM)
OpenNL, sparse linear solver.
CGAL packages: [Parameterization] [Solvers]

Selected Recorded Talks and Slides

Images and Animations

Optimal transport fluid sim: [2D] [3D] [Splash]
Taylor-Rayleigh instability [3D] [on sphere]
Geogram: [Recons] [Voronoi] [Transport]

Editorial activities and conferences

2014-18 The Visual Computer, Associate Editor
2014-18 GMOD, Associate Editor
2014-18 ACM Transactions on Graphics, Associate Editor
program co-chair of Computer Graphics Intl 2018
conference co-chair of WSOM 2017
conference co-chair of GMP 2016
2010-15: IEEE TVCG - Associate Editor
program co-chair of Eurographics 2014
conference co-chair of CAD Graph. 2013
program co-chair of Pacific Graph. 2013
program co-chair of ACM/EG SGP 2010
program co-chair of ACM SPM 2008
program co-chair of ACM SPM 2007

Program Commitees 2010-2017

2017: EG
2016: SGP, PG, SMI
2015: SIGGRAPH, SGP, GDSPM, CAD Graph.
2014: SGP
2013: SIGGRAPH, EG, SGP, DGCI, CGI
2012: SIGGRAPH, EG, SPM, SMI, SGP, PG, GMP, DGCI
2011: GPM, SMI, NORDIA, PG, SIBGRAPI
2010: SMI, SPM, GMP, NORDIA

Bruno Lévy's homepage