Data structures and the time complexity of ray tracing

The time complexity of ray tracing is a function of the data structures used for space division. Octree and hierarchical extents have been suggested as effective choices. In this paper, complexity parameters are suggested to characterize images and show that both octrees and hierarchies are appropriate choices if given most favorable images. Also, a unified technique is proposed and shown to be better than previous methods for all images. Octrees and hierarchies are particular cases of the new proposed algorithm.