NVidia’s Cyril Crassin has a great post on their Developer Blog talking about his in-depth research into realistic lighting in computer rendering.  Discussing realtime vs offline, along with many algorithms and physics effects, it’s a great-read.

The key to our approach lies in a new algorithm and data structure that allow much faster computation. Instead of working on triangles (the traditional way of rendering graphics), we’re using voxels. Each voxel is one value in a 3D grid. The voxels are stored in an octree structure (a tree structure in which each node has eight children), with voxels as the nodes on the tree. Octree structures effectively compact the information stored in large amounts of graphics data. Octree structures use less memory, making them faster and more efficient at rendering tasks such as ray tracing.

via An Inside Look At New Research On CG Global Illumination « NVIDIA.