Abstract
Light scattering in refractive media is an important optical phenomenon for computer graphics. While recent research has focused on multiple scattering, there has been less work on accurate solutions for single or low-order scattering. Refraction through a complex boundary allows a single external source to be visible in multiple directions internally with different strengths; these are hard to find with existing techniques. This paper presents techniques to quickly find paths that connect points inside and outside a medium while obeying the laws of refraction. We introduce: a half-vector based formulation to support the most common geometric representation, triangles with interpolated normals; hierarchical pruning to scale to triangular meshes; and, both a solver with strong accuracy guarantees, and a faster method that is empirically accurate. A GPU version achieves interactive frame rates in several examples.
Supplemental Material
Available for Download
This zip archive contains sample CUDA code for implementing our method for finding single scatter refractive paths on a GPU. It is meant as an illustrative example only.
- Bala, K., Walter, B., and Greenberg, D. P. 2003. Combining edges and points for interactive high-quality rendering. ACM Transactions on Graphics 22, 3, 631--640. Google ScholarDigital Library
- Chen, M., and Arvo, J. 2000. Theory and application of specular path perturbation. ACM Transactions on Graphics 19, 4, 246--278. Google ScholarDigital Library
- Ernst, M., Akenine-Möller, T., and Jensen, H. W. 2005. Interactive rendering of caustics using interpolated warped volumes. In Graphics Interface 2005, 87--96. Google ScholarDigital Library
- Estalella, P., Martin, I., Drettakis, G., and Tost, D. 2006. A gpu-driven algorithm for accurate interactive reflections on curved objects. In Rendering Techniques 2006 (Proc. EG Symp. on Rendering). Google ScholarDigital Library
- Hanrahan, P., and Krueger, W. 1993. Reflection from layered surfaces due to subsurface scattering. In Computer Graphics Proceedings, ACM SIGGRAPH, Annual Conference Series, 165--174. Google ScholarDigital Library
- Igehy, H. 1999. Tracing ray differentials. In Computer Graphics Proceedings, ACM SIGGRAPH, Annual Conference Series, 179--186. Google ScholarDigital Library
- Iwasaki, K., Dobashi, Y., and Nishita, T. 2003. A fast rendering method for refractive and reflective caustics due to water surfaces. Computer Graphics Forum 22, 3 (Sept.), 601--610.Google ScholarCross Ref
- Jarosz, W., Zwicker, M., and Jensen, H. W. 2008. The beam radiance estimate for volumetric photon mapping. Computer Graphics Forum (Proc. Eurographics '08) 27, 2. Google ScholarDigital Library
- Jensen, H. W., Marschner, S. R., Levoy, M., and Hanrahan, P. 2001. A practical model for subsurface light transport. In Computer Graphics Proc., ACM SIGGRAPH, Annual Conf. Series, 511--518. Google ScholarDigital Library
- Jensen, H. W. 2001. Realistic Image Synthesis Using Photon Mapping. AK Peters. Google ScholarDigital Library
- Krawczyk, R. 1969. Newton-algorithmen zur bestimmung von nullstellen mit fehlerschranken. Computing 4, 3, 187--201.Google ScholarCross Ref
- Mitchell, D., and Hanrahan, P. 1992. Illumination from curved reflectors. Computer Graphics (Proc. of Siggraph) 26, 3, 283--291. Google ScholarDigital Library
- Moore, R. E. 1977. A test for existence of solutions for non-linear systems. SIAM Journal on Numerical Analysis 14, 4, 611--615.Google ScholarCross Ref
- Nishita, T., and Nakamae, E. 1994. Method of displaying optical effects within water using accumulation buffer. In Computer Graphics Proceedings, ACM SIGGRAPH, Annual Conference Series, 373--379. Google ScholarDigital Library
- Nishita, T., Miyawaki, Y., and Nakamae, E. 1987. A shading model for atmospheric scattering considering luminous intensity distribution of light sources. Computer Graphics (Proc. of Siggraph) 21, 4, 303--310. Google ScholarDigital Library
- Ofek, E., and Rappoport, A. 1998. Interactive reflections on curved objects. In Computer Graphics Proceedings, ACM SIGGRAPH, Annual Conference Series, 333--342. Google ScholarDigital Library
- Popov, S., Günther, J., Seidel, H.-P., and Slusallek, P. 2007. Stackless kd-tree traversal for high performance gpu ray tracing. Computer Graphics Forum 26, 3 (Sept.), 415--424.Google ScholarCross Ref
- Rall, L. B. 1981. Automatic Differentiation: Techniques and Applications, vol. 120 of Lecture Notes in Computer Science. Springer.Google ScholarCross Ref
- Roger, D., and Holzschuch, N. 2006. Accurate specular reflections in real-time. Computer Graphics Forum (Proc. of EG 2006) 25, 3.Google Scholar
- Snyder, J. M. 1992. Interval analysis for computer graphics. Computer Graphics 26, 4 (July), 121--130. Google ScholarDigital Library
- Sun, B., Ramamoorthi, R., Narasimhan, S. G., and Nayar, S. K. 2005. A practical analytic single scattering model for real time rendering. ACM Transactions on Graphics 24, 3, 1040--1049. Google ScholarDigital Library
- Sun, X., Zhou, K., Stollnitz, E., Shi, J., and Guo, B. 2008. Interactive relighting of dynamic refractive objects. ACM Transactions on Graphics 27, 3 (Aug.), 35:1--35:9. Google ScholarDigital Library
- Szécsi, L. 2006. The hierarchical ray engine. In WSCG (Winter School of Computer Graphics).Google Scholar
- Szirmay-Kalos, L., Aszódi, B., Lazányi, I., and Premecz, M. 2005. Approximate ray-tracing on the GPU with distance impostors. Computer Graphics Forum (Proc. Eurographics '05) 24, 3.Google Scholar
- Veach, E., and Guibas, L. J. 1997. Metropolis light transport. In Computer Graphics Proceedings, ACM SIGGRAPH, Annual Conference Series, 65--76. Google ScholarDigital Library
- Walter, B., Fernandez, S., Arbree, A., Bala, K., Donikian, M., and Greenberg, D. P. 2005. Lightcuts: A scalable approach to illumination. ACM Transactions on Graphics 24, 3 (Aug.), 1098--1107. Google ScholarDigital Library
- Walter, B., Marschner, S. R., Li, H., and Torrance, K. E. 2007. Microfacet Models for Refraction through Rough Surfaces. In Rendering Techniques (Proc. EG Symposium on Rendering), 195--206. Google ScholarDigital Library
- Walter, B., Zhao, S., Holzschuch, N., and Bala, K. 2009. Supplemental to single scattering in refractive media with triangle mesh boundaries. Technical Report PCG-09-01, Cornell Program of Computer Graphics, June.Google Scholar
Index Terms
- Single scattering in refractive media with triangle mesh boundaries
Recommendations
Single scattering in refractive media with triangle mesh boundaries
SIGGRAPH '09: ACM SIGGRAPH 2009 papersLight scattering in refractive media is an important optical phenomenon for computer graphics. While recent research has focused on multiple scattering, there has been less work on accurate solutions for single or low-order scattering. Refraction ...
Accurate Computation of Single Scattering in Participating Media with Refractive Boundaries
Volume caustics are high-frequency effects appearing in participating media with low opacity, when refractive interfaces are focusing the light rays. Refractions make them hard to compute, since screen locality does not correlate with spatial locality ...
Point-Based Rendering for Homogeneous Participating Media with Refractive Boundaries
Illumination effects in translucent materials are a combination of several physical phenomena: refraction at the surface, absorption and scattering inside the material. Because refraction can focus light deep inside the material, where it will be ...
Comments