Refractive index dependent bidirectional scattering distribution functions.

We investigate the effect of immersing real-world materials into media of different refractive indices. We show, only some materials follow the Fresnel-governed behaviour. In reality, many materials exhibit unexpected effects such as stronger localized highlights or a significant increase in the glossy reflection due to microgeometry. We propose a parametric model that, however, takes their Fresnel-governed behaviour into account.