mental ray Architectural and Design Visualization Shader Library

2.3 Features 9The rules are as follows:• Transparency takes energy from Diffuse, i.e.diffuse at all.at 100% transparency, there will be no• Reflectivity takes energy from both Diffuse and Transparency, i.e. at 100% reflectivitythere will neither be any diffuse nor any transparency.• Translucency is a type of transparency, and refr trans w defines the percentage oftransparency vs. translucency.From left to right: Reflectivity 0.0, 0.4, 0.8 and 1.0From left to right: Transparencies 0.0, 0.4, 0.8 and 1.0It also means that the level of highlights is linked to the glossiness of a surface. A highrefl gloss value causes a narrower but very intense highlight, and a lower value causes awider but less intense highlight. This is because the energy is now spread out and dissipatedover a larger solid angle.2.3.3 BRDF - how Reflectivity Depends on AngleIn the real world, the reflectivity of a surface is often view angle dependent. A fancy termfor this is BRDF (Bi-directional Reflectance Distribution Function), i.e. a way to define howmuch a material reflects when seen from various angles.