Image wins Computer Graphics Forum cover competition

Leaf with relaxed photon mapped causticBen Spencer and Mark W. Jones won the 2009 Computer Graphics Forum cover competition with this image. The caustics underneath the sphere and leaf are generated using an enhanced photon mapping algorithm described in Into the Blue: Better Caustics through Photon Relaxation, Ben Spencer and Mark W. Jones, Eurographics 2009. The advantage of the approach is that low-noise radiance estimates may be achieved using very low bandwidth kernels. The caustic photon map in this scene contains 120,000 photons and only 50 are used in each radiance estimate. We can achieve good-quality results with as few as 20 photons. This results in the reduction of proximity, topology and boundary bias and also reduces the time required to render caustic illumination. The scene was created using a scan of a real leaf, post-processed and overlaid onto a translucent scattering dielectric film perturbed using a fractal noise function. Clip, gloss and bump maps were then created and the whole scene rendered using our own global illumination rendering platform.