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Depicting fire and other gaseous phenomena using diffusion processes
, 1995
"... Developing a visually convincing model of fire, smoke, and other gaseous phenomenais among the most difficult and attractive problems in computer graphics. We have created new methods of animating a wide range of gaseous phenomena, including the particularly subtle problem of modelling “wispy ” smok ..."
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Cited by 157 (4 self)
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Developing a visually convincing model of fire, smoke, and other gaseous phenomenais among the most difficult and attractive problems in computer graphics. We have created new methods of animating a wide range of gaseous phenomena, including the particularly subtle problem of modelling “wispy ” smoke and steam, using far fewer primitives than before. One significant innovation is the reformulation and solution of the advectiondiffusion equation for densities composed of “warped blobs”. These blobs more accurately model the distortions that gases undergo when advected by wind fields. We also introduce a simple model for the flame of a fire and its spread. Lastly, we present an efficient formulation and implementation of global illumination in the presence of gases and fire. Our models are specifically designed to permit a significant degree of user control over the evolution of gaseous phenomena.
Turbulent Wind Fields for Gaseous Phenomena
, 1993
"... The realistic depiction of smoke, steam, mist and water reacting to a turbulent field such as wind is an attractive and challenging problem. Its solution requires interlocking models for turbulent fields, gaseous flow, and realistic illumination. We present a model for turbulent wind flow having a d ..."
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Cited by 135 (11 self)
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The realistic depiction of smoke, steam, mist and water reacting to a turbulent field such as wind is an attractive and challenging problem. Its solution requires interlocking models for turbulent fields, gaseous flow, and realistic illumination. We present a model for turbulent wind flow having a deterministic component to specify largescale behaviour, and a stochastic component to model turbulent smallscale behaviour. The smallscale component is generated using spacetime Fourier synthesis. Turbulent wind fields can be superposed interactively to create subtle behaviour. An advectiondiffusion model is used to animate particlebased gaseous phenomena embedded in a wind field, and we derive an efficient physicallybased illumination model for rendering the system. Because the number of particles can be quite large, we present a clustering algorithm for efficient animation and rendering. CR Categories and Subject Descriptors: I.3.7 [Com puter Graphics]: ThreeDimensional Graphics...
Multiple Scattering as a Diffusion Process
 In Eurographics Rendering Workshop
, 1995
"... . Multiple scattering in participating media is generally a complex phenomenon. In the limit of an optically thick medium, i.e., when the mean free path of each photon is much smaller than the medium size, the effects of multiple scattering can be approximated by a diffusion process. We introduce ..."
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Cited by 117 (1 self)
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. Multiple scattering in participating media is generally a complex phenomenon. In the limit of an optically thick medium, i.e., when the mean free path of each photon is much smaller than the medium size, the effects of multiple scattering can be approximated by a diffusion process. We introduce this approximation from the radiative transfer literature to the computer graphics community and propose several numerical methods for its solution. We implemented both a multigrid finite differences scheme and a finiteelement blob method. 1
Stochastic Rendering of Density Fields
 Proceedings of Graphics Interface ’94
, 1994
"... Stochastic models are often economical to generate but problematic to render. Most previous algorithms first generate a realization of the stochastic model and then render it. These algorithms become expensive when the realization of the stochastic model is complex, because a large number of primiti ..."
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Cited by 25 (4 self)
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Stochastic models are often economical to generate but problematic to render. Most previous algorithms first generate a realization of the stochastic model and then render it. These algorithms become expensive when the realization of the stochastic model is complex, because a large number of primitives have to be rendered. In stochastic rendering we also model the intensity as a random field, and the statistics of the intensity field are related to the statistics of the stochastic model through an illumination model. Stochastic rendering algorithms then generate a realization of the intensity field directly from these statistics. In other words, a random component is shifted from the modelling to the rendering. This paradigm is not entirely new in computer graphics, so related work will be discussed. The main contribution of this paper is a stochastic rendering algorithm of gaseous phenomena modelled as random density fields such as clouds, smoke and fire. A simplified version of the ...
Turbulent Wind Fields for Gaseous Phenomena
"... The realistic depiction of smoke, steam, mist and water reacting to a turbulent field such as wind is an attractive and challenging problem. Its solution requires interlocking models for turbulent fields, gaseous flow, and realistic illumination. We present a model for turbulent wind flow having a d ..."
Abstract
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The realistic depiction of smoke, steam, mist and water reacting to a turbulent field such as wind is an attractive and challenging problem. Its solution requires interlocking models for turbulent fields, gaseous flow, and realistic illumination. We present a model for turbulent wind flow having a deterministic component to specify largescale behaviour, and a stochastic component to model turbulent smallscale behaviour. The smallscale component is generated using spacetime Fourier synthesis. Turbulent wind fields can be superposed interactively to create subtle behaviour. An advectiondiffusion model is used to animate particlebased gaseous phenomena embedded in a wind field, and we derive an efficient physicallybasedillumination model for rendering the system. Because the number of particles can be quite large, we present a clustering algorithm for efficient animation and rendering.