Publications of Lionel Utereiner

Publications HAL de untereiner de la structure shacra;mimesis

2016

Conference papers

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titre
Using Contours as Boundary Conditions for Elastic Registration during Minimally Invasive Hepatic Surgery
auteur
Nazim Haouchine, Frederick Roy, Lionel Untereiner, Stéphane Cotin
article
International Conference on Intelligent Robots and Systems, Oct 2016, Daejeon, South Korea
resume
We address in this paper the ill-posed problem of initial alignment of pre-operative to intra-operative data for augmented reality during minimally invasive hepatic surgery. This problem consists of finding the rigid transformation that relates the scanning reference and the endoscopic camera pose, and the non-rigid transformation undergone by the liver w.r.t its scanned state. Most of the state-of-the-art methods assume a known initial registration. Here, we propose a method that permits to recover the deformation undergone by the liver while simultaneously finding the rotational and translational parts of the transformation. Our formulation considers the boundaries of the liver with its surrounding tissues as hard constraints directly encoded in an energy minimization process. We performed experiments on real in-vivo data of human hepatic surgery and synthetic data, and compared our method with related works.
Accès au texte intégral et bibtex
https://hal.inria.fr/hal-01353185/file/haouchine_iros2016.pdf BibTex

2015

Journal articles

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titre
Virtual Cutting of Deformable Objects based on Efficient Topological Operations
auteur
Christoph Paulus, Lionel Untereiner, Hadrien Courtecuisse, Stephane Cotin, David Cazier
article
Visual Computer, Springer Verlag, 2015, 31 (6-8), pp.831-841. <10.1007/s00371-015-1123-x>
resume
Virtual cutting of deformable objects is at the core of many applications in interactive simulation and especially in computational medicine. The ability to simulate surgical cuts, dissection, soft tissue tearing ormicro-fractures is essential for augmenting the capabilities of existing or future simulation systems. To support such features,we combine a new remeshing algorithm with a fast finite element approach. The proposed method is generic enough to support a large variety of applications. We show the benefits of our approach evaluating the impact of cuts on the number of nodes and the numerical quality of the mesh. These points are crucial to ensure accurate and stable real-time simulations.
Accès au texte intégral et bibtex
https://hal.archives-ouvertes.fr/hal-01162099/file/2015CGI.pdf BibTex
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titre
CPH: a compact representation for hierarchical meshes generated by primal refinement
auteur
Lionel Untereiner, Pierre Kraemer, David Cazier, Dominique Bechmann
article
Computer Graphics Forum, Wiley, 2015, 34 (8), pp.155-166. <10.1111/cgf.12667>
resume
We present CPH (Compact Primal Hierarchy): a compact representation of the hierarchical connectivity of surface and volume manifold meshes generated through primal subdivision refinements. CPH is consistently defined in several dimensions and supports multiple kinds of tessellations and refinements, whether regular or adaptive. The basic idea is to store only the finest mesh, encoded in a classical monoresolution structure that is enriched with a minimal set of labels. These labels allow traversal of any intermediate level of the mesh concurrently without having to extract it in an additional structure. Our structure allows attributes to be stored on the cells not only on the finest level, but also on any intermediate level. We study the trade-off between the memory cost of this compact representation and the time complexity of mesh traversals at any resolution level.
Accès au texte intégral et bibtex
https://hal.archives-ouvertes.fr/hal-01162098/file/ihm.pdf BibTex

Conference papers

titre
Virtual Cutting of Deformable Objects based on Efficient Topological Operations
auteur
Christoph Paulus, Lionel Untereiner, Hadrien Courtecuisse, Stéphane Cotin, David Cazier
article
Computer Graphics International, 2015, Strasbourg, France. 2015
resume
Virtual cutting of deformable objects is at the core of many applications in interactive simulation and especially in computational medicine. The ability to simulate surgical cuts, dissection, soft tissue tearing ormicro-fractures is essential for augmenting the capabilities of existing or future simulation systems. To support such features,we combine a new remeshing algorithm with a fast finite element approach. The proposed method is generic enough to support a large variety of applications. We show the benefits of our approach evaluating the impact of cuts on the number of nodes and the numerical quality of the mesh. These points are crucial to ensure accurate and stable real-time simulations.
Accès au bibtex
BibTex

Preprints, Working Papers, …

titre
Hexahedral-dominant meshing
auteur
Dmitry Sokolov, Nicolas Ray, Lionel Untereiner, Bruno Lévy
article
2015
resume
This article introduces a method that generates a hexahedral-dominant mesh from an input tetrahedral mesh. It follows a three-steps pipeline similar to the one proposed by Carrier-Baudoin et al.: (1) generate a frame field; (2) generate a pointset P that is mostly organized on a regular grid locally aligned with the frame field; and (3) generate the hexahedral-dominant mesh by recombining the tetrahedra obtained from the constrained Delaunay triangulation of P. For step (1), we use a state of the art algorithm to generate a smooth frame field. For step (2), we introduce an extension of Periodic Global Parameterization to the volumetric case. As compared with other global parameterization methods (such as CubeCover), our method relaxes some global constraints and avoids creating degenerate elements, at the expense of introducing some singularities that are meshed using non-hexahedral elements. For step (3), we build on the formalism introduced by Meshkat and Talmor, fill-in a gap in their proof and provide a complete enumeration of all the possible recombinations, as well as an algorithm that efficiently detects all the matches in a tetrahedral mesh. The method is evaluated and compared with the state of the art on a database of examples with various mesh complexities, varying from academic examples to real industrial cases. Compared with the method of Carrier-Baudoin et al., the method results in better scores for classical quality criteria of hexahedral-dominant meshes (hexahedral proportion, scaled Jacobian, etc.). The method also shows better robustness than CubeCover and its derivatives when applied to complicated industrial models.
Accès au texte intégral et bibtex
https://hal.inria.fr/hal-01203544/file/PGP3D.pdf BibTex