ABSTRACT
Scattering in participating media, such as fog or haze, generates volumetric lighting effects known as crepuscular or god rays. Rendering such effects greatly enhances the realism in virtual scenes, but is inherently costly as scattering events occur at every point in space and thus it requires costly integration of the light scattered towards the observer. This is typically done using ray marching which is too expensive for every pixel on the screen for interactive applications. We propose a rendering technique for textured light sources in single-scattering media, that draws from the concept of epipolar geometry to place samples in image space: the inscattered light varies orthogonally to crepuscular rays, but mostly smoothly along these rays. These are epipolar lines of a plane of light rays that projects onto one line on the image plane. Our method samples sparsely along epipolar lines and interpolates between samples where adequate, but preserves high frequency details that are caused by shadowing of light rays. We show that our method is very simple to implement on the GPU, yields high quality images, and achieves high frame rates.
- Bavoil, L., Sainz, M., and Dimitrov, R. 2008. Image-space horizon-based ambient occlusion. In SIGGRAPH '08: ACM SIGGRAPH 2008 talks, ACM, New York, NY, USA, 1--1. Google ScholarDigital Library
- Biri, V., Arquès, D., and Michelin, S. 2006. Real time rendering of atmospheric scattering and volumetric shadows. Journal of WSCG'06 14(1), 65--72.Google Scholar
- Cerezo, E., Perez-Cazorla, F., Pueyo, X., Seron, F., and Sillion, F. 2005. A survey on participating media rendering techniques. The Visual Computer.Google Scholar
- Dobashi, Y., Yamamoto, T., and Nishita, T. 2002. Interactive rendering of atmospheric scattering effects using graphics hardware. In HWWS '02: Proceedings of the ACM SIGGRAPH/EUROGRAPHICS conference on Graphics hardware, Eurographics Association, 99--107. Google ScholarDigital Library
- Gautron, P., Marvie, J.-E., and François, G., 2009. Volumetric shadow mapping. ACM SIGGRAPH 2009 Sketches. Google ScholarDigital Library
- Hartley, R. I., and Zisserman, A. 2004. Multiple View Geometry in Computer Vision, second ed. Cambridge University Press, ISBN: 0521540518. Google ScholarDigital Library
- Hoffman, N., and Preetham, A. J. 2003. Real-time light-atmosphere interactions for outdoor scenes. 337--352. Google ScholarDigital Library
- Imagire, T., Johan, H., Tamura, N., and Nishita, T. 2007. Anti-aliased and real-time rendering of scenes with light scattering effects. The Visual Computer 23, 9, 935--944. Google ScholarDigital Library
- James, R. 2003. True volumetric shadows. In Graphics programming methods, Charles River Media, Inc., 353--366. Google ScholarDigital Library
- Jarosz, W., Zwicker, M., and Jensen, H. W. 2008. The beam radiance estimate for volumetric photon mapping. Computer Graphics Forum (Proc. Eurographics EG'08) 27, 2 (4), 557--566.Google Scholar
- Jensen, H. W., and Christensen, P. H. 1998. Efficient simulation of light transport in scences with participating media using photon maps. In SIGGRAPH '98, ACM, 311--320. Google ScholarDigital Library
- McMillan, Jr., L. 1997. An image-based approach to three-dimensional computer graphics. PhD thesis, Chapel Hill, NC, USA. Google ScholarDigital Library
- Mech, R. 2001. Hardware-accelerated real-time rendering of gaseous phenomena. In Journal of Graphics Tools, 6(3), 1--16. Google ScholarDigital Library
- Mitchell, J., 2004. Light shafts: Rendering shadows in participating media. Game Developers Conference 2004 Presentations.Google Scholar
- Mitchell, K. 2007. Volumetric light scattering as a post-process. GPU Gems 3, 275--285.Google Scholar
- Nichols, G., and Wyman, C. 2009. Multiresolution splatting for indirect illumination. In I3D '09: Proceedings of the 2009 symposium on Interactive 3D graphics and games, ACM, 83--90. Google ScholarDigital Library
- Pharr, M., and Humphreys, G. 2004. Physically Based Rendering: From Theory to Implementation. Morgan Kaufmann. Google ScholarDigital Library
- Policarpo, F., and Oliveira, M. M. 2006. Relief mapping of non-height-field surface details. In I3D '06: Proceedings of the 2006 symposium on Interactive 3D graphics and games, ACM, New York, NY, USA, 55--62. Google ScholarDigital Library
- Policarpo, F., Oliveira, M. M., and Comba, Jo a. L. D. 2005. Real-time relief mapping on arbitrary polygonal surfaces. In I3D '05: Proceedings of the 2005 symposium on Interactive 3D graphics and games, ACM, New York, NY, USA, 155--162. Google ScholarDigital Library
- Popescu, V., Mei, C., Dauble, J., and Sacks, E. 2006. Reflected-scene impostors for realistic reflections at interactive rates. Comput. Graph. Forum 25, 3, 313--322.Google ScholarCross Ref
- Sousa, T., 2008. Crysis next gen effects. Game Developers Conference 2008 Presentations.Google Scholar
- Sun, B., Ramamoorthi, R., Narasimhan, S. G., and Nayar, S. K. 2005. A practical analytic single scattering model for real time rendering. ACM Trans. Graph. 24, 3, 1040--1049. Google ScholarDigital Library
- Tóth, B., and Umenhoffer, T. 2009. Real-time volumetric lighting in participating media. In EUROGRAPHICS 2009 Short Papers.Google Scholar
- Wyman, C., and Ramsey, S. 2008. Interactive volumetric shadows in participating media with single scattering. In Proceedings of the IEEE Symposium on Interactive Ray Tracing, 87--92.Google Scholar
Index Terms
- Epipolar sampling for shadows and crepuscular rays in participating media with single scattering
Recommendations
Efficient simulation of light transport in scenes with participating media using photon maps
SIGGRAPH '98: Proceedings of the 25th annual conference on Computer graphics and interactive techniquesThis paper presents a new method for computing global illumination in scenes with participating media. The method is based on bidirectional Monte Carlo ray tracing and uses photon maps to increase efficiency and reduce noise. We remove previous ...
Radiance caching for participating media
In this article we present a novel radiance caching method for efficiently rendering participating media using Monte Carlo ray tracing. Our method handles all types of light scattering including anisotropic scattering, and it works in both homogeneous ...
Shadows and Soft Shadows with Participating Media Using Splatting
This paper describes an efficient algorithm to model the light attenuation due to a participating media with low albedo. Here, we consider the light attenuation along a ray, as well as the light attenuation emanating from a surface. The light ...
Comments