Irradiance regression for efficient final gathering in global illumination

Abstract

Photon mapping is widely used for global illumination rendering because of its high computational efficiency. But its efficiency is still limited, mainly by the intensive sampling required in final gathering, a process that is critical for removing low frequency artifacts of density estimation. In this paper, we propose a method to predict the final gathering estimation with direct density estimation, thereby achieving high quality global illumination by photon mapping with high efficiency. We first sample the irradiance of a subset of shading points by both final gathering and direct radiance estimation. Then we use the samples as a training set to predict the final gathered irradiance of other shading points through regression. Consequently, we are able to achieve about three times overall speedup compared with straightforward final gathering in global illumination computation with the same rendering quality.

Keywords

global illumination / photon mapping / final gathering / radiance estimation / regression

References

[1] Kajiya J T. The rendering equation. SIGGRAPH Comput. Graph., 1986, 20(4): 143-150

[2] Jensen H W. Realistic image synthesis using photon mapping. Natick, MA: A. K. Peters, Ltd., 2001

[3] Dutré P, Jensen H W, Arvo J, Bala K, Bekaert P, Marschner S, Pharr M. State of the art in monte carlo global illumination. In: Proceedings of ACM SIGGRAPH 2004 Course Notes. 2004

[4] Wald I, Mark W R, Günther J, Boulos S, Ize T, Hunt W, Parker S G, Shirley P. State of the art in ray tracing animated scenes. Computer Graphics Forum, 2007, 28(6): 1691-1722

[5] Ritschel T, Dachsbacher C, Grosch T, Kautz J. The state of the art in interactive global illumination. Computer Graphics Forum, 2012, 31(1): 160-188

[6] Lafortune E P, Willems Y D. Bi-directional path tracing. In: Proceedings of ACM SIGGRAPH. 1993, 145-153

[7] Keller A. Instant radiosity. In: Proceedings of the 24th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ’97. 1997, 49-56

[8] Jensen H W, Christensen N J. Photon maps in bidirectional Monte Carlo ray tracing of complex objects. Computers & Graphics, 1995, 19(2): 215-224

[9] Ward G J, Rubinstein FM, Clear R D. A ray tracing solution for diffuse interreflection. SIGGRAPH Comput. Graph., 1988, 22(4): 85-92

[10] Ward G J, Heckbert P S. Irradiance gradients. In: Proceedings of 3rd Eurographics Workshop on Rendering. 1992, 85-98

[11] Křivánek J, Gautron P, Ward G, Jensen H W, Christensen P H, Tabellion E. Practical global illumination with irradiance caching. In: Proceedings of ACM SIGGRAPH, 2008, 60:1-60:20

[12] Schwarzhaupt J, Jensen H W, Jarosz W. Practical hessian-based error control for irradiance caching. ACM Transactions on Graphics, 2012, 31(6): 193

[13] Spencer B, Jones M W. Into the blue: better caustics through photon relaxation. Computer Graphics Forum, 2009, 28(2): 319-328

[14] Hachisuka T, Ogaki S, Jensen HW. Progressive photon mapping. ACM Transactions on Graphics, 2008, 27(5): 130:1-130:8

[15] Hachisuka T, Jarosz W, Bouchard G, Christensen P, Frisvad J R, Jakob W, Jensen HW, Kaschalk M, Knaus C, Selle A, Spencer B. State of the art in photon density estimation. In: Proceedings of ACM SIGGRAPH 2012 Courses, SIGGRAPH ’12. 2012, 6:1-6:469

[16] Brouillat J, Bouville C, Loos B, Hansen C, Bouatouch K. A Bayesian monte carlo approach to global illumination. Computer Graphics Forum, 2009, 28(8): 2315-2329

[17] Marques R, Bouville C, Ribardière M, Santos L P, Bouatouch K. A spherical gaussian framework for Bayesian Monte Carlo rendering of glossy surfaces. IEEE Transactions on Visualization and Computer Graphics, 2013, 19(10): 1619-1632

[18] Sloan P P, Kautz J, Snyder J. Precomputed radiance transfer for real-time rendering in dynamic, low-frequency lighting environments. ACM Transactions on Graphics, 2002, 21(3): 527-536

[19] Wang J, Xu K, Zhou K, Lin S, Hu S M, Guo B. Spherical harmonics scaling. The Visual Computer, 2006, 22: 713-720

[20] Ng R, Ramamoorthi R, Hanrahan P. All-frequency shadows using nonlinear wavelet lighting approximation. ACM Transactions on Graphics, 2003, 22(3): 376-381

[21] Tsai Y T, Shih Z C. All-frequency precomputed radiance transfer using spherical radial basis functions and clustered tensor approximation. ACM Transactions on Graphics, 2006, 25(3): 967-976

[22] Xu K, Jia Y T, Fu H, Hu S M, Tai C L. Spherical piecewise constant basis functions for all-frequency precomputed radiance transfer. IEEE Transaction on Visualization and Computer Graphics, 2008, 14(2): 454-467

[23] Zhang Y, Dong Z, Ma K L. Real-time volume rendering in dynamic lighting environments using precomputed photon mapping. IEEE Transaction on Visualization Computer Graphics, 2013, 19(8): 1317-1330

[24] Zhou K, Hu Y, Lin S, Guo B, Shum H Y. Precomputed shadow fields for dynamic scenes. ACM Transactions on Graphics, 2005, 24(3): 1196-1201

[25] Ren Z, Wang R, Snyder J, Zhou K, Liu X, Sun B, Sloan P P, Bao H, Peng Q, Guo B. Real-time soft shadows in dynamic scenes using spherical harmonic exponentiation. ACM Transactions on Graphics, 2006, 25(3): 977-986

[26] Sun X, Zhou K, Chen Y, Lin S, Shi J, Guo B. Interactive relighting with dynamic brdfs. ACM Transactions on Graphics, 2007, 26(3): 27

[27] Wang R, Tran J, Luebke D. All-frequency interactive relighting of translucent objects with single and multiple scattering. ACM Transactions on Graphics, 2005, 24(3): 1202-1207

[28] Xu K, Gao Y, Li Y, Ju T, Hu S M. Real-time homogenous translucent material editing. Computer Graphics Forum, 2007, 26(3): 545-552

[29] Wang R, Cheslack-Postava E, Wang R, Luebke D, Chen Q, Hua W, Peng Q, Bao H. Real-time editing and relighting of homogeneous translucent materials. The Visual Computer, 2008, 24(7-9): 565-575

[30] Dachsbacher C, Stamminger M. Reflective shadow maps. In: Proceedings of the 2005 Symposium on Interactive 3D Graphics and Games, I3D ’05. 2005, 203-231

[31] Dachsbacher C, Stamminger M. Splatting indirect illumination. In: Proceedings of the 2006 Symposium on Interactive 3D Graphics and Games, I3D ’06. 2006, 93-100

[32] 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, 2008, 27(5): 129:1-129:8

[33] Ritschel T, Engelhardt T, Grosch T, Seidel H P, Kautz J, Dachsbacher C. Micro-rendering for scalable, parallel final gathering. ACM Transactions on Graphics, 2009, 28(5): 132:1-132:8

[34] 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, 2014, 33(1): 10:1-10:16

[35] Ramamoorthi R, Hanrahan P. An efficient representation for irradiance environment maps. In: Proceedings of the 28th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ’01. 2001, 497-500

[36] Wang R, Wang R, Zhou K, Pan M, Bao H. An efficient gpu-based approach for interactive global illumination. ACM Transactions<?Pub Caret?> on Graphics, 2009, 28(3): 91:1-91:8

[37] Wang J, Ren P, Gong M, Snyder J, Guo B. All-frequency rendering of dynamic, spatially-varying reflectance. ACM Transactions on Graphics, 2009, 28(5): 133:1-133:10

[38] Xu K, Sun W L, Dong Z, Zhao D Y, Wu R D, Hu S M. Anisotropic spherical gaussians. ACM Transactions on Graphics, 2013, 32(6): 209:1-209:11

[39] Ren P, Wang J, Gong M, Lin S, Tong X, Guo B. Global illumination with radiance regression functions. ACM Transactions on Graphics, 2013, 32(4): 130:1-130:12

[40] Roweis S T, Saul L K. Nonlinear dimensionality reduction by locally linear embedding. Science, 2000, 290(5500): 2323-2326

RIGHTS & PERMISSIONS

Higher Education Press and Springer-Verlag Berlin Heidelberg