Real-time BRDF editing in complex lighting

Abstract

Current systems for editing BRDFs typically allow users to adjust analytic parameters while visualizing the results in a simplified setting (e.g. unshadowed point light). This paper describes a real-time rendering system that enables interactive edits of BRDFs, as rendered in their final placement on objects in a static scene, lit by direct, complex illumination. All-frequency effects (ranging from near-mirror reflections and hard shadows to diffuse shading and soft shadows) are rendered using a precomputation-based approach. Inspired by real-time relighting methods, we create a linear system that fixes lighting and view to allow real-time BRDF manipulation. In order to linearize the image's response to BRDF parameters, we develop an intermediate curve-based representation, which also reduces the rendering and precomputation operations to 1D while maintaining accuracy for a very general class of BRDFs. Our system can be used to edit complex analytic BRDFs (including anisotropic models), as well as measured reflectance data. We improve on the standard precomputed radiance transfer (PRT) rendering computation by introducing an incremental rendering algorithm that takes advantage of frame-to-frame coherence. We show that it is possible to render reference-quality images while only updating 10% of the data at each frame, sustaining frame-rates of 25-30fps.

References

1. Agarwal, S., Ramamoorthi, R., Belongie, S., Jensen, H. 2003. Structured Importance Sampling of Environment Maps. ACM Transactions on Graphics (SIGGRAPH), 22, 3, 605--612.
2. Ashikhmin, M., Shirley, P. 2000a. An Anisotropic Phong BRDF Model. Journal of Graphics Tools, 5, 2, 25--32.
3. Ashikhmin, M., Premoze, S., Shirley, P. 2000b. A Microfacet-based BRDF generator. Proceedings of ACM SIGGRAPH 2000, 65--74.
4. Assarsson, U., Dougherty, M., Mounier, M., Moller, T. 2003, A Geometry-Based Soft Shadow Volume Algorithm Using Graphics Hardware. ACM Transactions on Graphics (SIGGRAPH), 22, 3, 511--520.
5. Ben-Artzi, A., Ramamoorthi, R., Agarwala, M. 2006. Efficient Shadows for Sampled Environment Maps. Journal of Graphics Tools, 11, 1, 13--36.
6. Blinn, J. F., 1977. Models of Light Reflection for Computer Synthesized Pictures. Computer Graphics and Interactive Techniques. 192--198.
7. Cook, R. L, Torrance, K. E., 1982. A Reflectance Model for Computer Graphics. ACM Transactions on Graphics, 1, 1, 7--24.
8. Daubechies, I. 1988. Orthonormal bases of compactly supported wavelets, Comm. Pure & Appl. Math., 41, 909--996.
9. Dana, K. J., B. Van Ginneken, S. K. Nayar, J. J. Koenderink: 1999, Reflectance and Texture of Real World Surfaces. ACM Transactions on Graphics, 18, 1, 1--34.
10. Ershov, S., Kolchin, K., Myszkowski, K., 2001. Rendering Pearlescent Appearance Based on Paint-Composition Modelling. Eurographics, 20, 3.
11. Jaroszkiewicz, R., McCool, M. 2003. Fast Extraction of BRDFs and Material Maps from Images. Graphics Interface 2003. 1--10.
12. Kautz, J., McCool, M. 1999. Interactive Rendering with Arbitrary BRDFs using Separable Approximations. Proceedings of the 10th Eurographics Workshop on Rendering. 281--292.
13. Lalonde, P., Fournier, A. 1997. A Wavelet Representation of Reflectance Functions. IEEE Trans. on Visualization & Comp. Graphics, 3(4) 329--336.
14. LaFortune, E., Foo, S., Torrance, K., Greenberg, D. 1997. Non-Linear Approximation of Reflectance Functions. ACM SIGGRAPH 97, 117--126.
15. Lawrence, J., Rusinkiewicz, S., Ramamoorthi, R. 2004. Efficient BRDF Importance Sampling Using a Factored Representation. ACM Transactions on Graphics (SIGGRAPH), 23, 3, 496--505.
16. Lawrence, J., Ben-Artzi, A., Decoro, C., Matusik, W., Pfister, H., Ramamoorthi, R., and Rusinkiewicz, S. 2006. Inverse Shade Trees for Non-Parametric Material Representation and Editing. ACM Transactions on Graphics (SIGGRAPH), 25, 3.
17. Liu, X., Sloan, P., Shum, H., Snyder, J. 2004. All-Frequency Precomputed Radiance Transfer for Glossy Objects. Eurographics Symposium on Rendering. 337--344.
18. Matusik, W., Pfister, H., Brand, M., McMillan, L. 2003. A Data-Driven Reflectance Model. ACM Transactions on Graphics (SIGGRAPH), 223, 3.
19. Maxwell, J. R., Beard, J., Weiner, S., Ladd, D. 1973. Bidirectional reflectance model validation and utilization. Technical Report AFAL-TR-73-303, Environmental Research Institute of Michigan (ERIM), October.
20. McAllister, D., Lastra, Al, Heidrich, W. 2002. Efficient Rendering of Spatial Bi-directional Reflectance Distribution Functions. Eurographics Workshop on Graphics Hardware, 79--88.
21. McCool, M., Ang, J., Ahmad, A. 2001. Homomorphic Factorization of BRDFs for High-Performance Rendering. Proceedings of ACM SIGGRAPH 2001, 171--178.
22. Ng, R., Ramamoorthi, R., Hanrahan, P. 2003. All-Frequency Shadows Using Non-Linear Wavelet Lighting Approximation. ACM Transactions on Graphics (SIGGRAPH), 22, 3, 376--381.
23. Ng, R., Ramamoorthi, R., Hanrahan, P. 2004. Triple product Wavelet Integrals for All-Frequency Relighting. ACM Transactions on Graphics (SIGGRAPH), 23, 3, 475--485.
24. Ngan, A., Durand, F., Matusik, W. 2005. Experimental Analysis of BRDF Models. Eurographics Symposium on Rendering. 117--126.
25. Nimeroff, J., Simoncelli, E., Dorsey, J. 1994. Efficient Rerendering of Naturally Illuminated Environments. Eurographics Rendering Workshop 94, 359--373.
26. Oren, M., Nayar, S. 1994. Generalization of Lambert's Reflectance Model. Proceedings of ACM SIGGRAPH 94. 239--246.
27. Pearl--A paint design tool. www.integra.jp/eng/products/pearl.
28. Pellacini, F., Vidimce, K., Lefohn, A. E., Mohr, A., Leone, M., and Warren, J. 2005. Lpics: A Hybrid Hardware-Accelerated Relighting Engine for Computer Cinematography. ACM Transactions on Graphics (SIGGRAPH). 24, 3, 464--470.
29. Phong, Bui Tuong. 1975. Illumination for Computer Generated Pictures. Communications of the ACM, 18, 6, 311--317.
30. Ramamoorthi, R., and Hanrahan, P. 2002. Frequency Space Environment Map Rendering. ACM Transactions on Graphics (SIGGRAPH), 21, 3.
31. Rusinkiewicz, S. 1998a. bv: graphics.stanford.edu/~smr/brdf/bv.
32. Rusinkiewicz, S. 1998b. A New Change of Variables for Efficient BRDF Representation. Eurographics Rendering Workshop 98, 11--22.
33. Schlick, C. 1994. An inexpensive BRDF Model for Physically-Based Rendering. Computer Graphics Forum (Eurographics), 13, 3, 233--246.
34. Sloan, P., Kautz, J., and Snyder, J. 2002. Precomputed Radiance Transfer for Real-Time Rendering in Dynamic, Low-Frequency Lighting Environments. ACM Transactions on Graphics (SIGGRAPH), 21, 3, 527--536.
35. Sloan, P., Kautz, J., and Snyder, J. 2003. Clustered Principal Components for Precomputed Radiance Transfer. ACM Transactions on Graphics (SIGGRAPH), 24, 3. 382--391.
36. Sloan, P., Luna, B., and Snyder, J. 2005. Local, Deformable Precomputed Radiance Transfer. ACM Transactions on Graphics (SIGGRAPH), 24, 3. 1216--1224.
37. Wan, L., Wong, T., and Leung, C. 2005. Spherical Q2-tree for Sampling Dynamic Environment Sequences. Eurographics Symposium on Rendering, 21--30.
38. Wang, R., Tran, J., and Luebke, D. 2004. All-Frequency Relighting of Non-Diffuse Objects using Separable BRDF Approximation. Eurographics Symposium on Rendering, 345--354
39. Ward, G. 1992. Measuring and Modeling Anisotropic Reflection, Proceeding of ACM SIGGRAPH 92. 265--272.
40. Zhou, K., Ju, Y., Lin, S., Guo, B., and Shum, H. 2005. Precomputed Shadow Fields for Dynamic Scenes. ACM Transactions on Graphics (SIGGRAPH), 25, 3. 1196--1201.

Index Terms

• Computing methodologies

  • Artificial intelligence

    • Computer vision

      • Computer vision problems

      • Computer vision tasks

        • Scene understanding

  • Computer graphics

    • Image manipulation

      • Texturing