
Interactive multiple anisotropic scattering in clouds
In Haines E. et Mcguire M. editors, ACM Symposium on Interactive 3D Graphics and Games, i3D. Redwood City, CA, Etats-Unis, février 2008. pages 173–182. ACM, 2008.
We propose an algorithm for the real time realistic simulation of multiple anisotropic scattering of light in a volume. Contrary to previous real-time methods we account for all kinds of light paths through the medium and preserve their anisotropic behavior.
Our approach consists of estimating the energy transport from the illuminated cloud surface to the rendered cloud pixel for each separate order of multiple scattering. We represent the distribution of light paths reaching a given viewed cloud pixel with the mean and standard deviation of their entry points on the lit surface, which we call the collector area. At rendering time for each pixel we determine the collector area on the lit cloud surface for different sets of scattering orders, then we infer the associated light transport. The fast computation of the collector area and light transport is possible thanks to a preliminary analysis of multiple scattering in planeparallel slabs and does not require slicing or marching through the volume.
Rendering is done efficiently in a shader on the GPU, relying on a cloud surface mesh augmented with a Hypertexture to enrich the shape and silhouette. We demonstrate our model with the interactive rendering of detailed animated cumulus and cloudy sky at 2-10 frames per second.
Our approach consists of estimating the energy transport from the illuminated cloud surface to the rendered cloud pixel for each separate order of multiple scattering. We represent the distribution of light paths reaching a given viewed cloud pixel with the mean and standard deviation of their entry points on the lit surface, which we call the collector area. At rendering time for each pixel we determine the collector area on the lit cloud surface for different sets of scattering orders, then we infer the associated light transport. The fast computation of the collector area and light transport is possible thanks to a preliminary analysis of multiple scattering in planeparallel slabs and does not require slicing or marching through the volume.
Rendering is done efficiently in a shader on the GPU, relying on a cloud surface mesh augmented with a Hypertexture to enrich the shape and silhouette. We demonstrate our model with the interactive rendering of detailed animated cumulus and cloudy sky at 2-10 frames per second.
Images et Films
Voir aussi
See also:- Cyril Crassin's master thesis (in French) for the GPU ray tracer
- The corresponding paper in French
- Our previous publication on stratiform clouds rendering at the EG Workshop on Natural Phenomena
- Antoine Bouthors's research page
- An english version of Cyril Crassin's work in some form
- A link to Antoine Bouthors's Ph.D. thesis (when it's done) with much more details
- More info on how to get the simulation data
- The I3D presentation slides
For now, if you are interested in the simulation data used in this paper, please contact the author directly.
Références BibTex
@inproceedings{BNMBC08,
author = {Antoine Bouthors and Fabrice Neyret and Nelson Max and \'Eric Bruneton and Cyril Crassin},
title = {Interactive multiple anisotropic scattering in clouds},
booktitle = {ACM Symposium on Interactive 3D Graphics and Games, i3D, February, 2008},
editor = {Eric Haines and Morgan Mcguire},
address = {Redwood City, CA, Etats-Unis},
publisher = {ACM},
pages = {173--182},
year = 2008
}
author = {Antoine Bouthors and Fabrice Neyret and Nelson Max and \'Eric Bruneton and Cyril Crassin},
title = {Interactive multiple anisotropic scattering in clouds},
booktitle = {ACM Symposium on Interactive 3D Graphics and Games, i3D, February, 2008},
editor = {Eric Haines and Morgan Mcguire},
address = {Redwood City, CA, Etats-Unis},
publisher = {ACM},
pages = {173--182},
year = 2008
}