NPH06: Natural Phenomena 2006

Permanent URI for this collection


A Generalized Cracks Simulation on 3D-Meshes

Valette, Gilles
Prévost, Stéphanie
Lucas, Laurent

Simulating Caustics due to Liquid-Solid Interface Menisci

Bourque, Eric
Dufort, Jean-François
Laprade, Michelle
Poulin, Pierre

Realistic Water Volumes in Real-Time

Baboud, Lionel
Décoret, Xavier

Time-Varying BRDFs

Sun, Bo
Sunkavalli, Kalyan
Ramamoorthi, Ravi
Belhumeur, Peter
Nayar, Shree

Real-time Realistic Illumination and Shading of Stratiform Clouds

Bouthors, Antoine
Neyret, Fabrice
Lefebvre, Sylvain

Physically-Based Realistic Fire Rendering

Pegoraro, Vincent
Parker, Steven G.

Artist-Directable Real-Time Rain Rendering in City Environments

Tatarchuk, Natalya
Isidoro, John

Effective Multi-resolution Rendering and Texture Compression for Captured Volumetric Trees

Linz, Christian
Reche-Martinez, Alex
Drettakis, George
Magnor, Marcus

Physically-based Driven Tree Animations

Haevre, William Van
Fiore, Fabian Di
Reeth, Frank Van


BibTeX (NPH06: Natural Phenomena 2006)
@inproceedings{
:10.2312/NPH/NPH06/007-014,
booktitle = {
Eurographics Workshop on Natural Phenomena},
editor = {
Norishige Chiba and Eric Galin
}, title = {{
A Generalized Cracks Simulation on 3D-Meshes}},
author = {
Valette, Gilles
and
Prévost, Stéphanie
and
Lucas, Laurent
}, year = {
2006},
publisher = {
The Eurographics Association},
ISSN = {1816-0867},
ISBN = {3-905673-38-X},
DOI = {
/10.2312/NPH/NPH06/007-014}
}
@inproceedings{
:10.2312/NPH/NPH06/033-040,
booktitle = {
Eurographics Workshop on Natural Phenomena},
editor = {
Norishige Chiba and Eric Galin
}, title = {{
Simulating Caustics due to Liquid-Solid Interface Menisci}},
author = {
Bourque, Eric
and
Dufort, Jean-François
and
Laprade, Michelle
and
Poulin, Pierre
}, year = {
2006},
publisher = {
The Eurographics Association},
ISSN = {1816-0867},
ISBN = {3-905673-38-X},
DOI = {
/10.2312/NPH/NPH06/033-040}
}
@inproceedings{
:10.2312/NPH/NPH06/025-032,
booktitle = {
Eurographics Workshop on Natural Phenomena},
editor = {
Norishige Chiba and Eric Galin
}, title = {{
Realistic Water Volumes in Real-Time}},
author = {
Baboud, Lionel
and
Décoret, Xavier
}, year = {
2006},
publisher = {
The Eurographics Association},
ISSN = {1816-0867},
ISBN = {3-905673-38-X},
DOI = {
/10.2312/NPH/NPH06/025-032}
}
@inproceedings{
:10.2312/NPH/NPH06/015-024,
booktitle = {
Eurographics Workshop on Natural Phenomena},
editor = {
Norishige Chiba and Eric Galin
}, title = {{
Time-Varying BRDFs}},
author = {
Sun, Bo
and
Sunkavalli, Kalyan
and
Ramamoorthi, Ravi
and
Belhumeur, Peter
and
Nayar, Shree
}, year = {
2006},
publisher = {
The Eurographics Association},
ISSN = {1816-0867},
ISBN = {3-905673-38-X},
DOI = {
/10.2312/NPH/NPH06/015-024}
}
@inproceedings{
:10.2312/NPH/NPH06/041-050,
booktitle = {
Eurographics Workshop on Natural Phenomena},
editor = {
Norishige Chiba and Eric Galin
}, title = {{
Real-time Realistic Illumination and Shading of Stratiform Clouds}},
author = {
Bouthors, Antoine
and
Neyret, Fabrice
and
Lefebvre, Sylvain
}, year = {
2006},
publisher = {
The Eurographics Association},
ISSN = {1816-0867},
ISBN = {3-905673-38-X},
DOI = {
/10.2312/NPH/NPH06/041-050}
}
@inproceedings{
:10.2312/NPH/NPH06/051-059,
booktitle = {
Eurographics Workshop on Natural Phenomena},
editor = {
Norishige Chiba and Eric Galin
}, title = {{
Physically-Based Realistic Fire Rendering}},
author = {
Pegoraro, Vincent
and
Parker, Steven G.
}, year = {
2006},
publisher = {
The Eurographics Association},
ISSN = {1816-0867},
ISBN = {3-905673-38-X},
DOI = {
/10.2312/NPH/NPH06/051-059}
}
@inproceedings{
:10.2312/NPH/NPH06/061-073,
booktitle = {
Eurographics Workshop on Natural Phenomena},
editor = {
Norishige Chiba and Eric Galin
}, title = {{
Artist-Directable Real-Time Rain Rendering in City Environments}},
author = {
Tatarchuk, Natalya
and
Isidoro, John
}, year = {
2006},
publisher = {
The Eurographics Association},
ISSN = {1816-0867},
ISBN = {3-905673-38-X},
DOI = {
/10.2312/NPH/NPH06/061-073}
}
@inproceedings{
:10.2312/NPH/NPH06/083-090,
booktitle = {
Eurographics Workshop on Natural Phenomena},
editor = {
Norishige Chiba and Eric Galin
}, title = {{
Effective Multi-resolution Rendering and Texture Compression for Captured Volumetric Trees}},
author = {
Linz, Christian
and
Reche-Martinez, Alex
and
Drettakis, George
and
Magnor, Marcus
}, year = {
2006},
publisher = {
The Eurographics Association},
ISSN = {1816-0867},
ISBN = {3-905673-38-X},
DOI = {
/10.2312/NPH/NPH06/083-090}
}
@inproceedings{
:10.2312/NPH/NPH06/075-082,
booktitle = {
Eurographics Workshop on Natural Phenomena},
editor = {
Norishige Chiba and Eric Galin
}, title = {{
Physically-based Driven Tree Animations}},
author = {
Haevre, William Van
and
Fiore, Fabian Di
and
Reeth, Frank Van
}, year = {
2006},
publisher = {
The Eurographics Association},
ISSN = {1816-0867},
ISBN = {3-905673-38-X},
DOI = {
/10.2312/NPH/NPH06/075-082}
}

Browse

Recent Submissions

Now showing 1 - 9 of 9
  • Item
    A Generalized Cracks Simulation on 3D-Meshes
    (The Eurographics Association, 2006) Valette, Gilles; Prévost, Stéphanie; Lucas, Laurent; Norishige Chiba and Eric Galin
    This article describes a method for simulating the formation and the development of cracks on the surface of a shrinking volume. The simulated cracks are applied afterwards to any surface provided with a parameterization. The 2D path of the cracks is automatically precalculated by an appropriate algorithm which gives a graph of discrete ways. We newly propose to take into account a possibly inhomogeneous thickness of the shrinking layer by using a watershed transformation to compute this path. The propagation of one crack is then based on the respect of the primary orientation of the crack. Another originality of our method is the calculation of the enlargement of each crack by a discrete shrinkage volume propagation. We consider the shrinking layer as a set of cubic cells which contain volumes of matter and pores. During the dessiccation process, the matter shrinks, creating what we call a shrinkage volume . We propagate this shrinkage volume among the cells up to the cracked ones, and we deduce the width of the cracks from the resulting shrinkage volume in these cells. In this paper, this method is presented in detail and we give images obtained from different simulations. Initially designed to help for the prediction of seedlings emergence in an agronomic environment, the method we present can also be applied to enhance the realism of virtual 3D objects.
  • Item
    Simulating Caustics due to Liquid-Solid Interface Menisci
    (The Eurographics Association, 2006) Bourque, Eric; Dufort, Jean-François; Laprade, Michelle; Poulin, Pierre; Norishige Chiba and Eric Galin
    A solid partially immersed in a liquid creates a local deformation of the liquid surface at their interface. This deformation, called a meniscus, exhibits high curvature, and as such, produces very intriguing caustic patterns. However, this natural phenomena has been neglected in almost all previous liquid simulation techniques. We propose a complete solution to model and render meniscal illumination effects. First, we outline a physicallymotivated approach to approximating the geometry of the meniscus. We then describe the targeted photon map, an adapted photon map which facilitates efficient sampling of the finely tessellated menisci. This technique, which integrates well within traditional photon mapping, allows for automatically rendering illumination effects for complex solid-liquid interfaces. Several images rendered using this technique are presented and are compared to their real-world counterparts.
  • Item
    Realistic Water Volumes in Real-Time
    (The Eurographics Association, 2006) Baboud, Lionel; Décoret, Xavier; Norishige Chiba and Eric Galin
    We present a real-time technique to render realistic water volumes. Water volumes are represented as the space enclosed between a ground heightfield and an animable water surface heightfield. This representation allows the application of recent GPU-based heightfield rendering algorithms. Our method is a simplified raytracing approach which correctly handles reflections and refractions and allows us to render complex effects such as light absorption, refracted shadows and refracted caustics. It runs at high framerates by exploiting the power of the latest graphic cards, and could be used in real-time applications like video games, or interactive simulation.
  • Item
    Time-Varying BRDFs
    (The Eurographics Association, 2006) Sun, Bo; Sunkavalli, Kalyan; Ramamoorthi, Ravi; Belhumeur, Peter; Nayar, Shree; Norishige Chiba and Eric Galin
    The properties of virtually all real-world materials change with time, causing their BRDFs to be time-varying. However, none of the existing BRDF models and databases take time variation into consideration; they represent the appearance of a material at a single time instance. In this work, we address the acquisition, analysis, modeling and rendering of a wide range of time-varying BRDFs. We have developed an acquisition system that is capable of sampling a material's BRDF at multiple time instances, with each time sample acquired within 36 seconds. We have used this acquisition system to measure the BRDFs of a wide range of time-varying phenomena which include the drying of various types of paints (watercolor, spray, and oil), the drying of wet rough surfaces (cement, plaster, and fabrics), the accumulation of dusts (household and joint compound) on surfaces, and the melting of materials (chocolate). Analytic BRDF functions are fit to these measurements and the model parameters' variations with time are analyzed. Each category exhibits interesting and sometimes non-intuitive parameter trends. These parameter trends are then used to develop analytic time-varying BRDF (TVBRDF) models. The analytic TVBRDF models enable us to apply effects such as paint drying and dust accumulation to arbitrary surfaces and novel materials.
  • Item
    Real-time Realistic Illumination and Shading of Stratiform Clouds
    (The Eurographics Association, 2006) Bouthors, Antoine; Neyret, Fabrice; Lefebvre, Sylvain; Norishige Chiba and Eric Galin
    Realistic rendering of clouds involves solving the complex interaction of light within the cloud and with its environment. Interactive methods achieve efficient cloud rendering by ignoring several lighting effects. However, these effects are visually important, and removing them strongly reduces realism. We present a novel approach for capturing the important effects of multiple anisotropic Mie scattering within cloud layers (i.e., stratiform clouds), and the inter-reflections between the ground and the cloud base under sun and sky illumination. Our model maps well to graphics hardware, enabling the real-time rendering of animated cloud skies over landscapes.
  • Item
    Physically-Based Realistic Fire Rendering
    (The Eurographics Association, 2006) Pegoraro, Vincent; Parker, Steven G.; Norishige Chiba and Eric Galin
    Accurately rendering fires is a challenging problem due to the various subtle ways in which the electromagnetic waves interact with this complex participating medium. We present a new method for physically-based rendering of flames from detailed simulations of flame dynamics which accounts for their unique characteristics. Instead of relying on ad-hoc models, we build on fundamental molecular physics to compute the spectrally dependent absorption, emission and scattering properties of the various chemical compounds found in the fire. Combined with a model of the refractive process, and with tone-mapping techniques simulating the visual adaptation of a human observer, we are able to generate highly realistic renderings of various types of flames, including colorful flames containing chemical species with very characteristic spectral properties.
  • Item
    Artist-Directable Real-Time Rain Rendering in City Environments
    (The Eurographics Association, 2006) Tatarchuk, Natalya; Isidoro, John; Norishige Chiba and Eric Galin
    Photorealistic rain greatly enhances the scenes of outdoor reality, with applications including computer games and motion pictures. Rain is a complex atmospheric natural phenomenon. It consists of numerous interacting visual effects. We present a comprehensive real-time system for the realistic rendering of rain effects in complex environments in real-time. Our system is intuitive, flexible and provides a high degree of artistic control for achieving the desired look. We describe a number of novel GPU-based algorithms for rendering the individual components of rain effects, such as a hybrid system of an image-space approach for rainfall and the particle-based effects for dripping raindrops and splashes; water surface simulation for ripples; animation and rendering of water droplets trickling down on transparent glass panes; view-dependent warped reflections and a number of additional effects. All our techniques respond dynamically and correctly to the environment lighting and viewpoint changes as well as the atmospheric illumination due to lightning. Our effects can be rendered at interactive rates on consumer graphics hardware and can be easily integrated into existing game and interactive application pipelines or offline rendering.
  • Item
    Effective Multi-resolution Rendering and Texture Compression for Captured Volumetric Trees
    (The Eurographics Association, 2006) Linz, Christian; Reche-Martinez, Alex; Drettakis, George; Magnor, Marcus; Norishige Chiba and Eric Galin
    Trees can be realistically rendered in synthetic environments by creating volumetric representations from photographs. However, volumetric tree representations created with previous methods are expensive to render due to the high number of primitives, and have very high texture memory requirements. We address both shortcomings by presenting an efficient multi-resolution rendering method and an effective texture compression solution. Our method uses an octree with appropriate textures at intermediate hierarchy levels and applies an effective pruning strategy. For texture compression, we adapt a vector quantization approach in a perceptually accurate color space, and modify the codebook generation of the Generalized Lloyd Algorithm to further improve texture quality. In combination with several hardware acceleration techniques, our approach achieves a reduction in texture memory requirements by one order of magnitude; in addition, it is now possible to render tens or even hundreds of captured trees at interactive rates.
  • Item
    Physically-based Driven Tree Animations
    (The Eurographics Association, 2006) Haevre, William Van; Fiore, Fabian Di; Reeth, Frank Van; Norishige Chiba and Eric Galin
    Simulating dynamic natural wind effects on trees remains a challenging task in Computer Graphics. From an animator s point of view it is a cumbersome and tedious task to create this effect due to the complexity of the tree shape, the numerous protruding branches and the wide variety of foliage. In this paper we present a novel method to create controllable animations of trees. Our approach borrows from several ideas from video textures, computer-assisted animation and motion graphs. It combines re-sequencing of existing material with the automatic generation of new data. Furthermore, the animator can direct the animation at each arbitrary moment using a goal based motion algorithm. First, a small set of motion data is gathered from a physically-based driven tree animation. Next, an optimised motion graph is constructed from the acquired data indicating all possible transitions from one tree pose to another. By creating in-between frames for all pairs of keyframes we ensure smooth transitions. Finally, by walking on the motion graph new non-identical animations are synthesised. The resulting animations are smooth, controllable by the animator and suitable for different production targets including 3D virtual environments (e.g., games) and 2D stylised animation.