A new model about BRDF defined by microfacet was developed for spatial object optical reflection modeling based on the principle of optical geometry and the technique of ray tracing.This model briefly contains the contribution to spatial object reflection characteristics by the microfacet normal direction

reflectivity and the shelter relation among microfacets.The diffuse reflection and the mirroring reflection are employed by this model in order to calculate the whole luminance characteristic and the local high luminance characteristic of spatial object.The result of validating work showed that the BRDF microfacet model curve is basically consistent as the actual measurement data curve.The rendering experiment expressly proved that the BRDF microfacet model could be used to simulate the effect exactly and calculate the optical reflection characteristic accurately of spatial object.