“Practical Hessian-based error control for irradiance caching”
Conference:
Type(s):
Title:
- Practical Hessian-based error control for irradiance caching
Session/Category Title: Global Illumination
Presenter(s)/Author(s):
Abstract:
This paper introduces a new error metric for irradiance caching that significantly outperforms the classic Split-Sphere heuristic. Our new error metric builds on recent work using second order gradients (Hessians) as a principled error bound for the irradiance. We add occlusion information to the Hessian computation, which greatly improves the accuracy of the Hessian in complex scenes, and this makes it possible for the first time to use a radiometric error metric for irradiance caching. We enhance the metric making it based on the relative error in the irradiance as well as robust in the presence of black occluders. The resulting error metric is efficient to compute, numerically robust, supports elliptical error bounds and arbitrary hemispherical sample distributions, and unlike the Split-Sphere heuristic it is not necessary to arbitrarily clamp the computed error thresholds. Our results demonstrate that the new error metric outperforms existing error metrics based on the Split-Sphere model and occlusion-unaware Hessians.
References:
1. Arvo, J., Torrance, K., and Smits, B. 1994. A framework for the analysis of error in global illumination algorithms. In Proceedings of SIGGRAPH 94, Computer Graphics Proceedings, Annual Conference Series, 75–84.
2. Arvo, J. 1994. The irradiance jacobian for partially occluded polyhedral sources. In Proceedings of the 21st annual conference on Computer graphics and interactive techniques, ACM, New York, NY, USA, SIGGRAPH ’94, 343–350.
3. Herzog, R., Myszkowski, K., and Seidel, H.-P. 2009. Anisotropic radiance-cache splatting for efficiently computing high-quality global illumination with lightcuts. In Computer Graphics Forum (Proc. Eurographics), Wiley-Blackwell, München, Germany, M. Stamminger and P. Dutré, Eds., vol. 28(2), 259–268.
4. Holzschuch, N., and Sillion, F. 1995. Accurate computation of the radiosity gradient for constant and linear emitters. In Rendering Techniques 1995 (Proceedings of the Eurographics Workshop on Rendering), Springer-Verlag, 186–195.
5. Holzschuch, N., and Sillion, F. X. 1998. An exhaustive error-bounding algorithm for hierarchical radiosity. Computer Graphics Forum 17, 4, 197–218.
6. Holzschuch, N. 1996. Le Contrôle de l’Erreur dans la Méthode de Radiosité Hiérarchique. PhD thesis, Université Joseph Fourier (Grenoble I).
7. Jarosz, W., Schönefeld, V., Kobbelt, L., and Jensen, H. W. 2012. Theory, analysis and applications of 2D global illumination. ACM Transactions on Graphics (Presented at ACM SIGGRAPH 2012) 31. to appear.
8. Křivánek, J., and Gautron, P. 2009. Practical Global Illumination with Irradiance Caching. Synthesis lectures in computer graphics and animation. Morgan & Claypool.
9. Křivánek, J., Gautron, P., Pattanaik, S., and Bouatouch, K. 2005. Radiance caching for efficient global illumination computation. IEEE Transactions on Visualization and Computer Graphics 11, 5 (Sept./Oct.), 550–561.
10. Křivánek, J., Bouatouch, K., Pattanaik, S., and Zára, J. 2006. Making radiance and irradiance caching practical: Adaptive caching and neighbor clamping. In Rendering Techniques 2006 (Proceedings of the Eurographics Symposium on Rendering), 127–138.
11. Křivánek, J., Gautron, P., Bouatouch, K., and Pattanaik, S. 2005. Improved radiance gradient computation. In SCCG ’05: Proceedings of the 21th spring conference on Computer graphics, ACM Press, New York, NY, USA, 155–159.
12. Larson, G. W., and Shakespeare, R. 1998. Rendering with Radiance: The Art and Science of Lighting Visualization. Morgan Kaufmann Publishers Inc., San Francisco, CA, USA.
13. Pharr, M., and Humphreys, G. 2010. Physically Based Rendering: From Theory to Implementation, 2nd ed. Morgan Kaufmann.
14. Ramamoorthi, R., Mahajan, D., and Belhumeur, P. 2007. A first-order analysis of lighting, shading, and shadows. ACM Transactions on Graphics 26, 1 (Jan.), 2:1–2:21.
15. Shirley, P., and Chiu, K. 1997. A low distortion map between disk and square. Journal of Graphics, GPU, and Game tools 2, 3, 45–52.
16. Shirley, P. S. 1991. Time complexity of Monte Carlo radiosity. In Eurographics ’91, 459–465.
17. Tabellion, E., and Lamorlette, A. 2004. An approximate global illumination system for computer generated films. ACM Transactions on Graphics (Proceedings of SIGGRAPH 2004) 23, 3 (Aug.), 469–476.
18. Ward, G. J., and Heckbert, P. S., 1992. Irradiance gradients.
19. Ward, G. J., Rubinstein, F. M., and Clear, R. D. 1988. A ray tracing solution for diffuse interreflection. SIGGRAPH Comput. Graph. 22 (June), 85–92.
