The Experts below are selected from a list of 108 Experts worldwide ranked by ideXlab platform
Annop Wongwathanarat - One of the best experts on this subject based on the ideXlab platform.
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a generalized solution for parallelized Computation of the three dimensional gravitational potential on a multipatch grid in spherical geometry
The Astrophysical Journal, 2019Co-Authors: Annop WongwathanaratAbstract:We present a generalized algorithm based on a spherical harmonics expansion method for efficient Computation of the three-dimensional gravitational potential on a multipatch grid in spherical geometry. Instead of solving for the gravitational potential by superposition of separate contributions from the mass density distribution on individual grid patches, our new algorithm directly computes the gravitational potential due to contributions from all grid patches in one Computation Step, thereby reducing the Computational cost of the gravity solver. This is possible by considering a set of angular weights that are derived from rotations of spherical harmonics functions defined in a global coordinate system that is common for all grid patches. Additionally, our algorithm minimizes data communication between parallel computing tasks by eliminating its proportionality to the number of subdomains in the grid configuration, making it suitable for parallelized Computation on a multipatch grid configuration with any number of subdomains. Test calculations of the gravitational potential of a triaxial ellipsoidal body with constant mass density on the Yin–Yang two-patch overset grid demonstrate that our method delivers the same level of accuracy as a previous method developed for the Yin–Yang grid while offering improved Computation efficiency and parallel scaling behavior.
Mathias Paulin - One of the best experts on this subject based on the ideXlab platform.
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Implicit Skinning: Real-Time Skin Deformation with Contact Modeling
ACM Transactions on Graphics, 2013Co-Authors: Rodolphe Vaillant, Loc Barthe, Gael Guennebaud, Marie-paule Cani, Damien Rohmer, Brian Wyvill, Olivier Gourmel, Mathias PaulinAbstract:Geometric skinning techniques, such as smooth blending or dualquaternions, are very popular in the industry for their high performances, but fail to mimic realistic deformations. Other methods make use of physical simulation or control volume to better capture the skin behavior, yet they cannot deliver real-time feedback. In this paper, we present the first purely geometric method handling skin contact effects and muscular bulges in real-time. The insight is to exploit the advanced composition mechanism of volumetric, implicit representations for correcting the results of geometric skinning techniques. The mesh is first approximated by a set of implicit surfaces. At each animation Step, these surfaces are combined in real-time and used to adjust the position of mesh vertices, starting from their smooth skinning position. This deformation Step is done without any loss of detail and seamlessly handles contacts between skin parts. As it acts as a post-process, our method fits well into the standard animation pipeline. Moreover, it requires no intensive Computation Step such as collision detection, and therefore provides real-time performances.
Rodolphe Vaillant - One of the best experts on this subject based on the ideXlab platform.
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Implicit Skinning: Real-Time Skin Deformation with Contact Modeling
ACM Transactions on Graphics, 2013Co-Authors: Rodolphe Vaillant, Loc Barthe, Gael Guennebaud, Marie-paule Cani, Damien Rohmer, Brian Wyvill, Olivier Gourmel, Mathias PaulinAbstract:Geometric skinning techniques, such as smooth blending or dualquaternions, are very popular in the industry for their high performances, but fail to mimic realistic deformations. Other methods make use of physical simulation or control volume to better capture the skin behavior, yet they cannot deliver real-time feedback. In this paper, we present the first purely geometric method handling skin contact effects and muscular bulges in real-time. The insight is to exploit the advanced composition mechanism of volumetric, implicit representations for correcting the results of geometric skinning techniques. The mesh is first approximated by a set of implicit surfaces. At each animation Step, these surfaces are combined in real-time and used to adjust the position of mesh vertices, starting from their smooth skinning position. This deformation Step is done without any loss of detail and seamlessly handles contacts between skin parts. As it acts as a post-process, our method fits well into the standard animation pipeline. Moreover, it requires no intensive Computation Step such as collision detection, and therefore provides real-time performances.
Dag Sverre Seljebotn - One of the best experts on this subject based on the ideXlab platform.
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wavemoth fast spherical harmonic transforms by butterfly matrix compression
Astrophysical Journal Supplement Series, 2012Co-Authors: Dag Sverre SeljebotnAbstract:We present Wavemoth, an experimental open source code for computing scalar spherical harmonic transforms (SHTs). Such transforms are ubiquitous in astronomical data analysis. Our code performs substantially better than existing publicly available codes owing to improvements on two fronts. First, the Computational core is made more efficient by using small amounts of pre-computed data, as well as paying attention to CPU instruction pipelining and cache usage. Second, Wavemoth makes use of a fast and numerically stable algorithm based on compressing a set of linear operators in a pre-Computation Step. The resulting SHT scales as O(L 2log2 L) for the resolution range of practical interest, where L denotes the spherical harmonic truncation degree. For low- and medium-range resolutions, Wavemoth tends to be twice as fast as libpsht, which is the current state-of-the-art implementation for the HEALPix grid. At the resolution of the Planck experiment, L ~ 4000, Wavemoth is between three and six times faster than libpsht, depending on the computer architecture and the required precision. Because of the experimental nature of the project, only spherical harmonic synthesis is currently supported, although adding support for spherical harmonic analysis should be trivial.
Brian Wyvill - One of the best experts on this subject based on the ideXlab platform.
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Implicit Skinning: Real-Time Skin Deformation with Contact Modeling
ACM Transactions on Graphics, 2013Co-Authors: Rodolphe Vaillant, Loc Barthe, Gael Guennebaud, Marie-paule Cani, Damien Rohmer, Brian Wyvill, Olivier Gourmel, Mathias PaulinAbstract:Geometric skinning techniques, such as smooth blending or dualquaternions, are very popular in the industry for their high performances, but fail to mimic realistic deformations. Other methods make use of physical simulation or control volume to better capture the skin behavior, yet they cannot deliver real-time feedback. In this paper, we present the first purely geometric method handling skin contact effects and muscular bulges in real-time. The insight is to exploit the advanced composition mechanism of volumetric, implicit representations for correcting the results of geometric skinning techniques. The mesh is first approximated by a set of implicit surfaces. At each animation Step, these surfaces are combined in real-time and used to adjust the position of mesh vertices, starting from their smooth skinning position. This deformation Step is done without any loss of detail and seamlessly handles contacts between skin parts. As it acts as a post-process, our method fits well into the standard animation pipeline. Moreover, it requires no intensive Computation Step such as collision detection, and therefore provides real-time performances.