1. A ray processing method, comprising: selecting, from among a plurality of traversal units based on a state of each of the plurality of traversal units, a traversal unit to process traversal of an input ray; and processing, by way of a processor, the traversal of the input ray using the selected traversal unit, wherein the state of each of the plurality of traversal units is determined based on a state one or more rays that are processed by each of the plurality of traversal units.