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Improved radiance gradient computation

Published: 11 August 2008 Publication History

Abstract

We describe a new and accurate algorithm for computing translational gradients of incoming radiance in the context of a ray tracingbased global illumination solution. The gradient characterizes how the incoming directional radiance function changes with displacement on a surface. We use the gradient for a smoother radiance interpolation over glossy surfaces in the framework of the radiance caching algorithm. The proposed algorithm generalizes the irradiance gradient computation by [Ward and Heckbert 1992] to allow its use for non-diffuse, glossy, surfaces. Compared to previous method for radiance gradient computation, the new algorithm yields better gradient estimates in the presence of significant occlusion changes in the sampled environment, allowing a smoother indirect illumination interpolation.

References

[1]
Annen, T., Kautz, J., Durand, F., and Seidel, H.-P. 2004. Spherical harmonic gradients for mid-range illumination. In Proceedings of the Eurographics Symposium on Rendering 2004.
[2]
Arvo, J. 1994. The irradiance jacobian for partially occluded polyhedral sources. In Proceedings of SIGGRAPH '94.
[3]
Gautron, P., Křivánek, J., Pattanaik, S. N., and Bouatouch, K. 2004. A novel hemispherical basis for accurate and efficient rendering. In Eurographics Symposium on Rendering.
[4]
Holzschuch, N., and Sillion, F. 1995. Accurate computation of the radiosity gradient with constant and linear emitters. In Sixth Eurographics Workshop on Rendering.
[5]
Křivánek, J., Gautron, P., Pattanaik, S., and Bouatouch, K. 2005. Radiance caching for efficient global illumination computation. Transactions on Visualization and Computer Graphics (accepted for publication). Also available as Technical Report #1623, IRISA, http://graphics.cs.ucf.edu/RCache/index.php.
[6]
Lafortune, E. P. F., Foo, S.-C., Torrance, K. E., and Greenberg, D. P. 1997. Non-linear approximation of reflectance functions. In Proceedings of SIGGRAPH '97.
[7]
Schröder, P., and Sweldens, W. 1995. Spherical wavelets: efficiently representing functions on the sphere. In Proceedings of SIGGRAPH, ACM Press, 161--172.
[8]
Ward, G. J., and Heckbert, P. S. 1992. Irradiance gradients. In Eurographics Workshop on Rendering.
[9]
Ward, G. J., Rubinstein, F. M., and Clear, R. D. 1988. A ray tracing solution for diffuse interreflection. In Proceedings of SIGGRAPH '88, 85--92.
[10]
Ward, G. J. 1992. Measuring and modeling anisotropic reflection. In Proceedings of SIGGRAPH '92, ACM Press, 265--272.
[11]
Westin, S. H., 2000. Lafortune BRDF for RenderMan. http://www.graphics.cornell.edu/westin/lafortune/lafortune.html.

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  1. Improved radiance gradient computation

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    cover image ACM Conferences
    SIGGRAPH '08: ACM SIGGRAPH 2008 classes
    August 2008
    5354 pages
    ISBN:9781450378451
    DOI:10.1145/1401132
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    Publication History

    Published: 11 August 2008

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    Author Tags

    1. global illumination
    2. irradiance gradients
    3. radiance caching
    4. radiance gradients
    5. ray tracing

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