对表面光滑、基底面漫射的吸收-散射性半透明涂层,通过建立入射光谱的辐射传递模型,采用蒙特卡罗法求解分析了涂层光学厚度、介质散射及基底面反射对涂层表面双向反射特性的影响.结果表明,即使在不考虑涂层表面Fresnel反射的条件下,吸收-散射性半透明涂层的反射也呈现明显的各向异性,其BRDF分布与吸收性半透明涂层的BRDF特性有明显差别.

For the absorbing-scattering semitransparent coatings with smooth surface and diffuse opaque substrate,the propagation model of the incident spectrum was derived and the spectral radiative transfer was solved by Monte Carlo method.The effects of the optical thickness,medium scattering and substrate reflection on the bi-directional reflection of the coating surface were analyzed.The results show that the reflection of an absorbing-scattering semitransparent coating is obviously anisotropic even if the Fresnel reflection on surface is not taken into account,and its BRDF is quite different from that of an absorbing coating.