Abstract: Ray tracing is an important method to resolve global illumination. We think that the tracing is the study on the light crossing and efficient sampling.This paper provided a survey on ray tracing algorithms.We introduced the research on real-time ray tracing and GPU based ray tracing, which is the hotspot at present. We pointed out the advantage and disadvantage of ray tracing based global illumination, and the research pivot in the near future. In the end,we prospected the application foreground of ray tracing based global illumination.

Key words: Ray tracing, Global illumination, Light crossing, Sampling, Dynamic scenes