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January 23, 2013

Speaker: William Sherif, MSc Student, Ontario Tech University

Title: Real-Time Global Illumination Techniques

Abstract: A number of techniques for displaying global illumination in real-time appeared in the past fifteen years or so. Baked-in radiosity has been used in games since Quake in 1996. Precomputed radiance transfer was first published by Sloan in 2002. Screen-space methods based on deferred shading techniques such as SSAO and SSDO were developed in 2007 and 2009 respectively. In 2011, the first AAA title to use real-time radiosity was released. Real-time ray tracing is not very common yet, but several demo applications exist, showing RTRT is possible on modern GPUs.

We present two new ideas. Spherical harmonics are introduced as an alternative to spherical harmonics, by substituting the Chebyshev polynomial in the place of the Legendre polynomial as the orthogonal polynomial in the spherical harmonics definition. Vector occluders are introduced as a novel, precomputed, real-time, empirical technique for adding global illumination effects to a locally illuminated scene on static geometry.