Pascal Gautron

Pascal Gautron
NVIDIA | Nvidia · Advanced Rendering Center, Berlin, DE

PhD

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49
Publications
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699
Citations

Publications

Publications (49)
Chapter
Full-text available
Spatial hashing is a very efficient approach for storing sparse spatial data in a way that easily allows merging information among areas with similar properties. Though having a very simple core, this technique requires careful implementation to achieve high efficiency. In this chapter we first consider some key principles and implementation aspect...
Patent
Full-text available
The invention relates to a method for estimation of information representative of a height. In order to minimize the required calculation time, the method comprises steps for: selection of a first point from among a plurality of points of a normal map, a normal being associated with each of the points of said plurality, a reference height being as...
Patent
Full-text available
The invention relates to a method for estimating the quantity of light scattered by a heterogeneous participating media, the light being transmitted by a light environment comprising a plurality of light sources. In order to improve the display while minimising the required calculation time, the method comprises steps for: estimation of first proj...
Conference Paper
Full-text available
The limited resolution of shadow maps (SM) may result in er-roneous shadowing, yielding artificially jagged edges and tempo-rally crawling shadows even using perspective optimization tech-niques. We introduce Sub-Pixel Shadow Maps (SPSM) for real-time shadow-mapping with sub-pixel precision. Our technique is based on the storage of a fixed-size par...
Article
We introduce Boundary-Aware Extinction Maps for interactive rendering of massive heterogeneous volumetric datasets. Our approach is based on the projection of the extinction along light rays into a boundary-aware function space, focusing on the most relevant sections of the light paths. This technique also provides an alternative representation of...
Conference Paper
The limited resolution of shadow maps may result in erroneous shadowing, yielding artificially jagged edges (Figure 1) and temporally crawling shadows even using perspective optimization techniques. Dai et al. [2008] propose an explicit storage of geometry within shadow map texels to avoid aliasing. Each texel stores the coordinates of the closest...
Conference Paper
Full-text available
We present a Many-Core Event Evaluation framework for real-time execution of many complex animation schemes applicable to a wide range of domains such as gaming and interactive pre-visualization in studio production. Our technique takes advantages of task parallelism on many-core CPU architecture using a two-level scheduling approach. Our generic a...
Article
Full-text available
GPU Shape Grammars provide a solution for interactive procedural generation, tuning and visualization of massive environment elements for both video games and production rendering. Our technique generates detailed models without explicit geometry storage. To this end we reformulate the grammar expansion for generation of detailed models at the tess...
Article
Full-text available
The simulation of the lighting effects produced by the interaction of participating media with the light contributes to the production of visually compelling effects such as translucence and volumetric shadowing. However, the complex inner structure of participating media requires vast amounts of memory for storage and costly computations for rende...
Conference Paper
Full-text available
Participating media are an unavoidable part of todays visual effects. The computation of compelling lighting effects within clouds or smoke remains challenging, both in terms of memory occupancy and computational power. Also, the fine tuning and layout of production-quality scenes requires efficient techniques for fast pre-visualization of the resu...
Article
The interaction between light and participating media involves complex physical phenomena such as light absorption and scattering. The radiance transmitted through a medium then depends on the variations of scattering and extinction along potentially complex light paths, yielding soft light shafts and shadowing (Figure 1).
Conference Paper
Virtual worlds feature increasing geometric and shading complexities, resulting in a constant need for effective solutions to avoid rendering objects invisible for the viewer. This observation is particularly true in the context of real-time rendering of highly occluded environments such as urban areas, landscapes or indoor scenes. This problem has...
Conference Paper
As the trend of online multi-user worlds gets more and more momentum, such worlds usually require heavy infrastructures both in terms of hardware and software: servers often manage the entire world simulation, and hence limit the number of simultaneous connections. The data exchanges are performed using proprietary protocols, requiring specific ser...
Conference Paper
Full-text available
Realistic lighting of virtual scenes has been a widely researched domain for decades. Many recent methods for realistic rendering make extensive use of image-based lighting, in which a real lighting environment is captured and reused to light virtual objects. However, the capture of such lighting environments usually requires still scenes and speci...
Conference Paper
Full-text available
Ambient occlusion (AO) [Pharr and Green 2004] provides an approximation to global illumination. It can be computed in real-time if restricted to screen-space [Mittring 2007; Loos and Sloan 2010], at the cost of an approximation of solutions computed in geometric space, thus introducing a loss of quality.
Conference Paper
Full-text available
The interaction between light and participating media involves complex physical phenomena including light absorption and scattering. Media such as fog, clouds or smoke feature complex lighting interactions that are intrinsically related to the properties of their constitutive particles. As a result, the radiance transmitted by the medium depends on...
Conference Paper
Full-text available
We introduce procedural geometry mapping and ray-dependent grammar development for fast and scalable render-time generation of procedural geometric details on graphics hardware. By leveraging the properties of the widely used split grammars, we replace geometry generation by lazy per-pixel grammar development. This approach drastically reduces the...
Conference Paper
Full-text available
The interaction between light and light-transmitting objects, known as participating media, involves complex physical phenomena such as light absorption and scattering. Media such as clouds, smoke and translucent materials often feature heterogeneous scattering properties. Hence the radiance transmitted by the medium potentially depends on such var...
Article
Full-text available
As virtual worlds applications get more and more demanding in terms of world complexity and rendering qual-ity, rendering virtual terrains and planets in real-time introduces many challenges. In this paper, we provide a full-featured solution for rendering of arbitrary large terrain datasets in the context of client-server streaming. Our solution a...
Article
Full-text available
We present a method for fast volume rendering using graphics hardware (GPU). To our knowledge, it is the first imple-mentation on the GPU. Based on the Shear-Warp algorithm, our GPU-based method provides real-time frame rates and outperforms the CPU-based implementation. When the number of slices is not sufficient, we add in-between slices computed...
Article
Full-text available
Rendering realistic organic materials is a challenging issue. The human eye is an important part of nonverbal communication which, consequently, requires specific modeling and rendering techniques to enhance the realism of virtual characters. We propose an image-based method for estimating both iris morphology and scattering features in order to ge...
Article
Irradiance caching is a ray tracing-based technique for computing global illumination on diffuse surfaces. Specifically, it addresses the computation of indirect illumination bouncing off one diffuse object onto another. The sole purpose of irradiance caching is to make this computation reasonably fast. The main idea is to perform the indirect illu...
Conference Paper
Classical rendering methods usually consider that light travels in vacuum, hence overlooking its interactions with its medium of transmission: the air. However, interactions between light and particles in suspension in the air generate phenomena such as smoke, fog, dust... Existing methods for simulating such interactions often rely on the native f...
Article
Full-text available
We describe a generic solution for remote adaptive streaming and rendering of large terrains. The challenge is to ensure a fast rendering and a rapidly improving quality with any user interaction, network capacity and rendering system performance. We adapt to these constraints so loading and rendering speeds do not depend on the size of the databas...
Chapter
Most global illumination methods only focus on static scenes. Accounting for animated objects and light sources either require a recomputation of the global illumination solution for each frame or involve complex data structures and algorithms for temporal optimization [SKDM05]. Furthermore, global illumination solutions in dynamic scenes commonly...
Chapter
In this chapter, we treat the irradiance caching algorithm as a black box and we focus on its efficient integration in the process of computing full global illumination solution.
Chapter
As described in the previous chapter, a straightforward way to compute indirect illumination at a point on a diffuse surface is hemisphere sampling: a number of secondary rays are traced and their radiance contributions are averaged. However, doing so at each visible point is prohibitive, since many rays must be traced to obtain results free of vis...
Chapter
In the classical irradiance caching algorithm, the irradiance cache is queried for each visible point in the scene to determine if a new irradiance record should be created. When a new record is required, the irradiance value is computed by sampling the surrounding hemisphere using ray tracing. The newly created record is then stored inanoctree, ca...
Chapter
This chapter discusses some details that make rendering with irradiance caching more practical. Section 3.1 shows that the order in which pixels are visited during image rendering may have a significant impact on the caching performance and image quality. In Section 3.2 we focus on maintaining a good performance of irradiance caching in complex sce...
Chapter
Our visual perception of reality is due to the light entering our eyes. But before the light reaches the eyes on its way from the light source, it is usually reflected or refracted many times off object surfaces. In computer graphics, we refer to the light bouncing around in a scene as global illumination. Depending on the objects’ reflective mater...
Patent
Full-text available
The invention relates to a method for the synthesis of an iris image (II), characterised in that a pixel (p) of the image is determined by establishing a correspondence with one or more points (Mp) of an iris photograph (PI) obtained by filtering reflected light, said correspondence being determined using a de-refraction function.
Patent
Full-text available
The invention relates to a method for the synthesis of an iris image (II), characterised in that a pixel (p) of the image is determined by establishing a correspondence with one or more points (Mp) of an iris photograph (PI) obtained by filtering reflected light, said correspondence being determined using a de-refraction function.
Article
We describe a global illumination method combining two well known techniques: photon mapping and irradiance caching. The photon mapping method has the advantage of being view independent but requires a costly additional rendering pass, called final gathering. As for irradiance caching, it is view-dependent, irradiance is only computed and cached on...
Article
Full-text available
New gradients Gradients by [Křivánek et al. 2005] Figure 1: Right: The gradient computation proposed by [Křivánek et al. 2005] does not properly handle significant change of occlusion in the sampled environment and leaves visible interpolation artifacts. Left: The radiance gradient computation proposed in this paper handles occlusion changes and le...
Conference Paper
Since its invention 20 years ago, irradiance caching has been successfully used to accelerate global illumination computation in the Radiance lighting simulation system. Its widespread use had to wait until computers became fast enough to consider global illumination in production rendering. Since then, its use is ubiquitous. Virtually all commerci...
Conference Paper
Very often global illumination methods aim at simulating the light/matter interactions within static scenes. Accounting for the displacement of objects and light sources either require a complete recomputation of the global illumination solution for each frame of the animation, or involve complex data structures and algorithms for temporal optimiza...
Conference Paper
Fast global illumination computation is a challenge in several fields such as lighting simulation and computergenerated visual effects for movies. To this end, the irradiance caching algorithm is commonly used since it provides high-quality rendering in a reasonable time. However this algorithm relies on a spatial data structure in which nearest-ne...
Conference Paper
We apply simplified image-based lighting methods to reduce the equipment, cost, time, and specialized skills required for high-quality photographic lighting of desktop-sized static objects such as museum artifacts. We place the object and a computer-steered ...
Article
Full-text available
Recovering anatomical features of organic materials is a challenging issue. The human eye, as an important part of the non verbal communication, needs to be accurately modeled and rendered to increase the realism of virtual characters. The recent improvements of the graphics hardware offer the opportunity of rendering complex organic materials, fol...
Article
Full-text available
We present a novel method for fast, high quality computation of glossy global illumination in animated environments. Building on the irradiance caching and radiance caching algorithms, our method leverages temporal coherence by sparse temporal sampling and interpolation of the indirect lighting. In our approach, part of the global illumination solu...
Article
Full-text available
In this paper, we present a ray tracing-based method for accelerated global illumination computation in scenes with low-frequency glossy BRDFs. The method is based on sparse sampling, caching, and interpolating radiance on glossy surfaces. In particular, we extend the irradiance caching scheme proposed by Ward et al. to cache and interpolate direct...
Conference Paper
Full-text available
Fast global illumination computation is a challenge in several fields such as lighting simulation and computer- generated visual effects for movies. To this end, the irradiance caching algorithm is commonly used since it provides high-quality rendering in a reasonable time. However this algorithm relies on a spatial data structure in which nearest-...
Article
In this paper we present a ray tracing based method for accelerated global illumination computation in scenes with low-frequency glossy BRDFs. The method is based on sparse sampling, caching, and interpolating radiance on glossy surfaces. In particular we extend the irradiance caching scheme proposed by Ward et al. [1] to cache and interpolate dire...
Conference Paper
Full-text available
This paper presents a new set of hemispherical basis functions dedicated to hemispherical data representation. These functions are derived from associated Legendre polynomials. We demonstrate the usefulness of this basis for representation of surface reectance functions, rendering using environment maps and for efcient global il- lumination computa...

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