Cone tracing

Cone tracing is a derivative of the ray tracing algorithm that replaces rays, which have no thickness, with cones. Cone tracing is related to beam tracing, but uses circular rather than polygonal cross sections.

Cone tracing solves certain problems related to sampling and aliasing, which can plague conventional ray tracing. However, cone tracing creates a host of problems of its own. For example, just intersecting a cone with scene geometry leads to an enormous variety of possible results. For this reason, cone tracing has remained mostly unpopular. In recent years, increases in computer speed have made Monte Carlo algorithms like distributed ray tracing much more viable than cone tracing.

However, a recent SVO implementation by Crassin et al^[1] has shown remarkable promise, demonstrating global illumination of remarkable quality at 25-70 frames per second^[2].

References

1. ^ Cyril Crassin, Fabrice Neyret, Miguel Sainz, Simon Green, Elmar Eisemann. Interactive Indirect Illumination Using Voxel Cone Tracing: A Preview.
2. ^ http://www.youtube.com/watch?v=fAsg_xNzhcQ