As an important phenomenon of outdoor scene

atmospheric degradation was paid increasing attention in the field of both computer vision and computer graphics.Based on the theory of Radiative Transfer

the paper is to explore the techniques of computer graphics relating to this phenomenon.Building on an extended path tracer

it describes an integrated rendering framework of atmospheric degradation

which makes the ray walk randomly both through the space of scene but the domain of spectrum.Also it introduces an analytic model of sky and the detail of implementation is described.