Abstract
This paper proposes a modification of the filtered importance sampling method, and improves the quality of virtual spherical Gaussian light (VSGL)-based real-time glossy indirect illumination using this modification. The original filtered importance sampling method produces large overlaps of and gaps between filtering kernels for high-frequency probability density functions (PDFs). This is because the size of the filtering kernel is determined using the PDF at the sampled center of the kernel. To reduce those overlaps and gaps, this paper determines the kernel size using the integral of the PDF within the filtering kernel. Our key insight is that these integrals are approximately constant, if kernel centers are sampled using stratified sampling. Therefore, an appropriate kernel size can be obtained by solving this integral equation. Using the proposed kernel size for filtered importance sampling-based VSGL generation, undesirable artifacts are significantly reduced with a negligibly small overhead.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
References
Krivánek, J.; Colbert, M. Real-time shading with filtered importance sampling. Computer Graphics Forum Vol. 27, No. 4, 1147–1154, 2008.
Tokuyoshi, Y. Virtual spherical Gaussian lights for real-time glossy indirect illumination. Computer Graphics Forum Vol. 34, No. 7, 89–98, 2015.
Dachsbacher, C.; Stamminger, M. Reflective shadow maps. In: Proceedings of the 2005 Symposium on Interactive 3D Graphics and Games, 203–231, 2005.
Keller, A. Instant radiosity. In: Proceedings of the 24th Annual Conference on Computer Graphics and Interactive Techniques, 49–56, 1997.
Dong, Z.; Grosch, T.; Ritschel, T.; Kautz, J.; Seidel, H.-P. Real-time indirect illumination with clustered visibility. In: Proceedings of the Vision, Modeling, and Visualization Workshop, 187–196, 2009.
Prutkin, R.; Kaplanyan, A. S.; Dachsbacher, C. Reflective shadow map clustering for real-time global illumination. In: Proceedings of Eurographics 2012 (Short Papers), 9–12, 2012.
Ritschel, T.; Grosch, T.; Kim, M. H.; Seidel, H.-P.; Dachsbacher, C.; Kautz, J. Imperfect shadow maps for efficient computation of indirect illumination. ACM Transactions on Graphics Vol. 27, No. 5, Article No. 129, 2008.
Agarwal, S.; Ramamoorthi, R.; Belongie, S.; Jensen, H. W. Structured importance sampling of environment maps. ACM Transactions on Graphics Vol. 22, No. 3, 605–612, 2003.
Debevec, P. A median cut algorithm for light probe sampling. In: Proceedings of SIGGRAPH 2005 Posters, Article No. 66, 2005.
Ritschel, T.; Eisemann, E.; Ha, I.; Kim, J. D. K.; Seidel, H.-P. Making imperfect shadow maps viewadaptive: High-quality global illumination in large dynamic scenes. Computer Graphics Forum Vol. 30, No. 8, 2258–2269, 2011.
Dachsbacher, C.; Krivánek, J.; Hasan, M.; Arbree, A.; Walter, B.; Novák, J. Scalable realistic rendering with many-light methods. Computer Graphics Forum Vol. 33, No. 1, 88–104, 2014.
Clarberg, P.; Jarosz, W.; Akenine-Möller, T.; Jensen, H. W. Wavelet importance sampling: Efficiently evaluating products of complex functions. ACM Transactions on Graphics Vol. 24, No. 3, 1166–1175, 2005.
Dachsbacher, C.; Stamminger, M. Splatting indirect illumination. In: Proceedings of the 2006 Symposium on Interactive 3D Graphics and Games, 93–100, 2006.
Ritschel, T.; Dachsbacher, C.; Grosch, T.; Kautz, J. The state of the art in interactive global illumination. Computer Graphics Forum Vol. 31, No. 1, 160–188, 2012.
Barák, T.; Bittner, J.; Havran, V. Temporally coherent adaptive sampling for imperfect shadow maps. Computer Graphics Forum Vol. 32, No. 4, 87–96, 2013.
Krivánek, J.; Ferwerda, J. A.; Bala, K. Effects of global illumination approximations on material appearance. ACM Transactions on Graphics Vol. 29, No. 4, Article No. 112, 2010.
Luksch, C.; Tobler, R. F.; Habel, R.; Schwrzler, M.; Wimmer, M. Fast light-map computation with virtual polygon lights. In: Proceedings of the ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games, 87–94, 2013.
Tsai, Y.-T.; Shih, Z.-C. All-frequency precomputed radiance transfer using spherical radial basis functions and clustered tensor approximation. ACM Transactions on Graphics Vol. 25, No. 3, 967–976, 2006.
Xu, K.; Sun, W.-L.; Dong, Z.; Zhao, D.-Y.; Wu, R.- D.; Hu, S.-M. Anisotropic spherical Gaussians. ACM Transactions on Graphics Vol. 32, No. 6, Article No. 209, 2013.
Iwasaki, K.; Dobashi, Y.; Nishita, T. Interactive bi-scale editing of highly glossy materials. ACM Transactions on Graphics Vol. 31, No. 6, Article No. 144, 2012.
Iwasaki, K.; Mizutani, K.; Dobashi, Y.; Nishita, T. Interactive cloth rendering of microcylinder appearance model under environment lighting. Computer Graphics Forum Vol. 33, No. 2, 333–340, 2014.
Wang, J.; Ren, P.; Gong, M.; Snyder, J.; Guo, B. All-frequency rendering of dynamic, spatially-varying reflectance. ACM Transactions on Graphics Vol. 28, No. 5, Article No. 133, 2009.
Xu, K.; Ma, L.-Q.; Ren, B.; Wang, R.; Hu, S.-M. Interactive hair rendering and appearance editing under environment lighting. ACM Transactions on Graphics Vol. 30, No. 6, Article No. 173, 2011.
Yan, L.-Q.; Zhou, Y.; Xu, K.; Wang, R. Accurate translucent material rendering under spherical Gaussian lights. Computer Graphics Forum Vol. 31, No. 7, 2267–2276, 2012.
Xu, K.; Cao, Y.-P.; Ma, L.-Q.; Dong, Z.; Wang, R.; Hu, S.-M. A practical algorithm for rendering interreflections with all-frequency BRDFs. ACM Transactions on Graphics Vol. 33, No. 1, Article No. 10, 2014.
Tokuyoshi, Y. Fast indirect illumination using two virtual spherical Gaussian lights. In: Proceedings of SIGGRAPH Asia 2015 Posters, Article No. 12, 2015.
Crassin, C.; Neyret, F.; Sainz, M.; Green, S.; Eisemann, E. Interactive indirect illumination using voxel cone tracing. Computer Graphics Forum Vol. 30, No. 7, 1921–1930, 2011.
Xu, C.; Wang, R.; Bao, H. Realtime rendering glossy to glossy reflections in screen space. Computer Graphics Forum Vol. 34, No. 7, 57–66, 2015.
Sloan, I. H.; Joe, S. Lattice Methods for Multiple Integration. Oxford University Press, 1994.
Hedman, P.; Karras, T.; Lehtinen, J. Sequential Monte Carol instant radiosity. In: Proceedings of the 20th ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games, 121–128, 2016.
Blinn, J. F. Models of light reflection for computer synthesized pictures. ACM SIGGRAPH Computer Graphics Vol. 11, No. 2, 192–198, 1977.
Beckmann, P.; Spizzichino, A. The Scattering of Electromagnetic Waves from Rough Surfaces. New York: MacMillan, 1963.
Trowbridge, T. S.; Reitz, K. P. Average irregularity representation of a rough surface for ray reflection. Journal of the Optical Society of America Vol. 65, No. 5, 531–536, 1975.
Walter, B.; Marschner, S. R.; Li, H.; Torrance, K. E. Microfacet models for refraction through rough surfaces. In: Proceedings of the 18th Eurographics Conference on Rendering Techniques, 195–206, 2007.
Toksvig, M. Mipmapping normal maps. Journal of Graphics Tools Vol. 10, No. 3, 65–71, 2005.
Kajiya, J. T. The rendering equation. ACM SIGGRAPH Computer Graphics Vol. 20, No. 4, 143–150, 1986.
Hasan, M.; Krivánek, J.; Walter, B.; Bala, K. Virtual spherical lights for many-light rendering of glossy scenes. ACM Transactions on Graphics Vol. 28, No. 5, Article No. 143, 2009.
Karras, T. Maximizing parallelism in the construction of BVHs, octrees, and k-d trees. In: Proceedings of the 4th ACM SIGGRAPH/Eurographics Conference on High-Performance Graphics, 33–37, 2012.
Merrill, D. G.; Grimshaw, A. S. Revisiting sorting for GPGPU stream architectures. In: Proceedings of the 19th International Conference on Parallel Architectures and Compilation Technique, 545–546, 2010.
Author information
Authors and Affiliations
Corresponding author
Additional information
This article is published with open access at Springerlink.com
Yusuke Tokuyoshi is a senior researcher at Square Enix. He received his Ph.D. degree in engineering from Shinshu University in 2007. Before joining Square Enix, he engaged in R&D on compiler optimization at Hitachi, Ltd. His interests include global illumination algorithms and real-time rendering.
Open Access The articles published in this journal are distributed under the terms of the Creative Commons Attribution 4.0 International License (http:// creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Other papers from this open access journal are available free of charge from http://www.springer.com/journal/41095. To submit a manuscript, please go to https://www. editorialmanager.com/cvmj.
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
About this article
Cite this article
Tokuyoshi, Y. Modified filtered importance sampling for virtual spherical Gaussian lights. Comp. Visual Media 2, 343–355 (2016). https://doi.org/10.1007/s41095-016-0063-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s41095-016-0063-3