Abstract: While raytracing, the screen image pixel is decomposed into the combination of radiance
and texture of the patches, created as scene objects intersect with the casting ray. The radiance of each
patch is calculated at the linear combination of the bases of bi-directional reflectance distribution
function (BRDF), and able to be accelerated by graphics processing unit (GPU) parallel rendering.
This paper presents a global illumination rendering algorithm based on BRDF and GPU parallel
computation. With GPU parallel acceleration, through improving the efficiency of rendering, the
algorithm achieves global illumination real-time rendering of the scene including dynamic interactive
material. The key research: object surface’s multiple reflection characteristic is represented by linear
combination of the basis of BRDF, so transforming the nonlinear problem to a linear one, thus
improve the rendering efficiency. With GPU parallel acceleration, the algorithm calculates the object
surface’s radiation energy and texture mapping and their linear combination, further improving the
efficiency of rendering to meet the requirement of real-time.

Key words: global illumination, graphics processing unit, bidirectional reflectance distribution function;
rendering equation, parallel computing