Issue No. 10 - Oct. (2012 vol. 18)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TVCG.2011.282
Charles de Rousiers , INRIA Rhone-Alpes, Grenoble
Adrien Bousseau , INRIA Sophia-Antipolis, Sophia-Antipolis
Kartic Subr , University College London, London
Nicolas Holzschuch , INRIA Rhone-Alpes, Grenoble
Ravi Ramamoorthi , University of California, Berkeley, Berkeley
We present an algorithm to render objects made of transparent materials with rough surfaces in real-time, under all-frequency distant illumination. Rough surfaces cause wide scattering as light enters and exits objects, which significantly complicates the rendering of such materials. We present two contributions to approximate the successive scattering events at interfaces, due to rough refraction: First, an approximation of the Bidirectional Transmittance Distribution Function (BTDF), using spherical Gaussians, suitable for real-time estimation of environment lighting using preconvolution; second, a combination of cone tracing and macrogeometry filtering to efficiently integrate the scattered rays at the exiting interface of the object. We demonstrate the quality of our approximation by comparison against stochastic ray tracing. Furthermore we propose two extensions to our method for supporting spatially varying roughness on object surfaces and local lighting for thin objects.
Surface roughness, Real time systems, Rough surfaces, Geometry, Scattering, Lighting, normal distribution function., Real-time rendering, translucent material, bidirectional transmittance distribution function
K. Subr, N. Holzschuch, R. Ramamoorthi, C. de Rousiers and A. Bousseau, "Real-Time Rendering of Rough Refraction," in IEEE Transactions on Visualization & Computer Graphics, vol. 18, no. , pp. 1591-1602, 2012.