In the interactive graphics applications such as games and augmented reality which require high demanding real time performance

the adoption of complex environment lighting has been increasing to illuminate the synthetic objects naturally in the dynamic scenes and make them merge consistently.we propose the Cook Torrance illumination model to accomplish the illumination computing.Our method analyze spherical harmonics to determine the lighting coefficients of high dynamic range environment map in real time and use them to obtain a quadratic polynomial form of high dynamic range environment map.Then calculate the expression in the shader to obtain the diffuse component of the illumination model. And the specular component of it is approximated via the technology of environment maps.Finally all of them are computed in GPU. The experimental results show our algorithm renders the synthetic objects at rates of over 30 FPS under dynamic complex environment lighting and achieves photo-realistic visual effect.