RESUMO
We model the visual appearance of thin, semi-transparent metallic films coated on arbitrary three-dimensional substrates, incorporating effects including nanoscale film roughness, microscale substrate roughness, and source of light. Film reflectance is modeled by combining electrodynamic simulations with the Schlick approximation, which is adapted and validated to describe the color appearance of thin semi-transparent metallic films with nanoscale, subwavelength roughness. Diffuse scattering originating from microscale roughness of the substrate and partial reflectance is described by a microfacet model. Photorealistic rendered images generated by our approach are qualitatively compared to photographs of fabricated thin-film samples under similar lighting conditions. We render images of semi-transparent metallic films as a function of film thickness, multilayer composition, substrate type, nanoscale film roughness, microscale substrate roughness, and environmental lighting, yielding physically plausible results consistent with previously reported observations.
