This paper by Larsen et al. at Technical University of Denmark introduces a fast GPU accelerated technique for simulating photon mapping. Each of the steps in the photon mapping algorithm are executed either on the CPU or the GPU depending on which of the processors are most appropriate for the task. The indirect illumination is calculated using a new GPU accelerated final gathering method. Caustic photons are traced on the CPU and then drawn using points in the framebuffer, and finally filtered using the GPU. Both diffuse and non-diffuse surfaces are handled by calculating the direct illumination on the GPU and the photon tracing on the CPU. (Simulating Photon Mapping for Real-time Applications. Bent D. Larsen, Niels J. Christensen, To appear at Eurographics Symposium on Rendering, 2004.)