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Mathias Paulin

Bio: Mathias Paulin is an academic researcher from University of Toulouse. The author has contributed to research in topics: Rendering (computer graphics) & Global illumination. The author has an hindex of 17, co-authored 57 publications receiving 970 citations. Previous affiliations of Mathias Paulin include Centre national de la recherche scientifique & Paul Sabatier University.


Papers
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Journal ArticleDOI
21 Jul 2013
TL;DR: This paper presents the first purely geometric method handling skin contact effects and muscular bulges in real-time, and it requires no intensive computation step such as collision detection, and therefore provides real- time performances.
Abstract: Geometric skinning techniques, such as smooth blending or dual-quaternions, 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.

123 citations

Proceedings ArticleDOI
26 Jun 2006
TL;DR: The key idea of the method is to use the shadow map as a simple and uniform discretized represention of the scene, thus allowing us to generate realistic soft shadows in most cases.
Abstract: We present a new real-time soft shadow algorithm using a single shadow map per light source. Therefore, our algorithm is well suited to render both complex and dynamic scenes, and it handles all rasterizable geometries. The key idea of our method is to use the shadow map as a simple and uniform discretized represention of the scene, thus allowing us to generate realistic soft shadows in most cases. In particular it naturally handles occluder fusion. Also, our algorithm deals with rectangular light sources as well as textured light sources with high precision, and it maps well to programmable graphics hardware.

112 citations

Journal ArticleDOI
TL;DR: This review puts forward the practical consequences of writing down and handling the integral formulation associated to each Monte Carlo algorithm and tries to argue that these formulations are very much accessible to the non specialist and that they allow a straightforward entry to sensitivity computations and convergence enhancement techniques involving subtle concepts such as control variate and zero variance.

101 citations

Journal ArticleDOI
TL;DR: A new family of binary composition operators is introduced that solves four major problems of constructive implicit modeling: suppressing bulges when two shapes merge, avoiding unwanted blending at a distance, ensuring that the resulting shape keeps the topology of the union, and enabling sharp details to be added without being blown up.
Abstract: We introduce a new family of binary composition operators that solves four major problems of constructive implicit modeling: suppressing bulges when two shapes merge, avoiding unwanted blending at a distance, ensuring that the resulting shape keeps the topology of the union, and enabling sharp details to be added without being blown up. The key idea is that field functions should not only be combined based on their values, but also on their gradients. We implement this idea through a family of C∞ composition operators evaluated on the GPU for efficiency, and illustrate it by applications to constructive modeling and animation.

67 citations

Journal ArticleDOI
TL;DR: A new visibility computation procedure based on the detection of occluder contours, that is more accurate and faster while reducing aliasing and a view‐dependent adaptive strategy, that automatically reduces the screen resolution in the region of large penumbrae, thus allowing us to keep very high frame rates in any situation.
Abstract: The recent soft shadow mapping technique allows the rendering in real-time of convincing soft shadows on complex and dynamic scenes using a single shadow map. While attractive, this method suffers from shadow overestimation and becomes both expensive and approximate when dealing with large penumbrae. This paper proposes new solutions removing these limitations and hence providing an efficient and practical technique for soft shadow generation. First, we propose a new visibility computation procedure based on the detection of occluder contours which is more accurate and faster while reducing aliasing. Secondly, we present a shadow map multi-resolution strategy keeping the computation complexity almost independent on the light size while maintaining high-quality rendering. Finally, we propose a view dependent adaptive strategy, that automatically reduces the screen resolution in the region of large penumbrae, thus allowing us to keep very high frame rates in any situation.

64 citations


Cited by
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Book
01 Dec 1988
TL;DR: In this paper, the spectral energy distribution of the reflected light from an object made of a specific real material is obtained and a procedure for accurately reproducing the color associated with the spectrum is discussed.
Abstract: This paper presents a new reflectance model for rendering computer synthesized images. The model accounts for the relative brightness of different materials and light sources in the same scene. It describes the directional distribution of the reflected light and a color shift that occurs as the reflectance changes with incidence angle. The paper presents a method for obtaining the spectral energy distribution of the light reflected from an object made of a specific real material and discusses a procedure for accurately reproducing the color associated with the spectral energy distribution. The model is applied to the simulation of a metal and a plastic.

1,401 citations

Proceedings ArticleDOI
29 Jul 2007
TL;DR: This paper presents a new Point Set Surface (PSS) definition based on moving least squares (MLS) fitting of algebraic spheres, and presents an novel normal estimation procedure which exploits the properties of the spherical fit for both direction estimation and orientation propagation.
Abstract: In this paper we present a new Point Set Surface (PSS) definition based on moving least squares (MLS) fitting of algebraic spheres. Our surface representation can be expressed by either a projection procedure or in implicit form. The central advantages of our approach compared to existing planar MLS include significantly improved stability of the projection under low sampling rates and in the presence of high curvature. The method can approximate or interpolate the input point set and naturally handles planar point clouds. In addition, our approach provides a reliable estimate of the mean curvature of the surface at no additional cost and allows for the robust handling of sharp features and boundaries. It processes a simple point set as input, but can also take significant advantage of surface normals to improve robustness, quality and performance. We also present an novel normal estimation procedure which exploits the properties of the spherical fit for both direction estimation and orientation propagation. Very efficient computational procedures enable us to compute the algebraic sphere fitting with up to 40 million points per second on latest generation GPUs.

474 citations

Journal ArticleDOI
TL;DR: This article surveys Heterogeneous Computing Techniques (HCTs) such as workload partitioning that enable utilizing both CPUs and GPUs to improve performance and/or energy efficiency and reviews both discrete and fused CPU-GPU systems.
Abstract: As both CPUs and GPUs become employed in a wide range of applications, it has been acknowledged that both of these Processing Units (PUs) have their unique features and strengths and hence, CPU-GPU collaboration is inevitable to achieve high-performance computing. This has motivated a significant amount of research on heterogeneous computing techniques, along with the design of CPU-GPU fused chips and petascale heterogeneous supercomputers. In this article, we survey Heterogeneous Computing Techniques (HCTs) such as workload partitioning that enable utilizing both CPUs and GPUs to improve performance and/or energy efficiency. We review heterogeneous computing approaches at runtime, algorithm, programming, compiler, and application levels. Further, we review both discrete and fused CPU-GPU systems and discuss benchmark suites designed for evaluating Heterogeneous Computing Systems (HCSs). We believe that this article will provide insights into the workings and scope of applications of HCTs to researchers and motivate them to further harness the computational powers of CPUs and GPUs to achieve the goal of exascale performance.

414 citations

Journal ArticleDOI
01 Dec 2009
TL;DR: A point cloud with noise, outliers, non-uniformities, and in particular interference between close-by surface sheets is consolidated as a preprocess to surface generation, focusing on reliable normal estimation.
Abstract: We consolidate an unorganized point cloud with noise, outliers, non-uniformities, and in particular interference between close-by surface sheets as a preprocess to surface generation, focusing on reliable normal estimation. Our algorithm includes two new developments. First, a weighted locally optimal projection operator produces a set of denoised, outlier-free and evenly distributed particles over the original dense point cloud, so as to improve the reliability of local PCA for initial estimate of normals. Next, an iterative framework for robust normal estimation is introduced, where a priority-driven normal propagation scheme based on a new priority measure and an orientation-aware PCA work complementarily and iteratively to consolidate particle normals. The priority setting is reinforced with front stopping at thin surface features and normal flipping to enable robust handling of the close-by surface sheet problem. We demonstrate how a point cloud that is well-consolidated by our method steers conventional surface generation schemes towards a proper interpretation of the input data.

375 citations

Journal ArticleDOI
TL;DR: The Edge-Aware Resampling algorithm is demonstrated to be capable of producing consolidated point sets with noise-free normals and clean preservation of sharp features, and to lead to improved performance of edge-aware reconstruction methods and point set rendering techniques.
Abstract: Points acquired by laser scanners are not intrinsically equipped with normals, which are essential to surface reconstruction and point set rendering using surfels. Normal estimation is notoriously sensitive to noise. Near sharp features, the computation of noise-free normals becomes even more challenging due to the inherent undersampling problem at edge singularities. As a result, common edge-aware consolidation techniques such as bilateral smoothing may still produce erroneous normals near the edges. We propose a resampling approach to process a noisy and possibly outlier-ridden point set in an edge-aware manner. Our key idea is to first resample away from the edges so that reliable normals can be computed at the samples, and then based on reliable data, we progressively resample the point set while approaching the edge singularities. We demonstrate that our Edge-Aware Resampling (EAR) algorithm is capable of producing consolidated point sets with noise-free normals and clean preservation of sharp features. We also show that EAR leads to improved performance of edge-aware reconstruction methods and point set rendering techniques.

358 citations