mental ray Architectural and Design Visualization Shader Library

26 2 Architectural MaterialA transparency of 0.75 and a refr trans w of 0.0 (left), 0.5 (center) and 1.0 (right)• If refr trans w is 0.0, all of the transparency is used for transparency.• If refr trans w is 0.5, half of the transparency is used for transparency and half isused for translucency.• If refr trans w is 1.0, all of the transparency is used for translucency and there is noactual transparency.The translucency is primarily intended to be used in “thin walled” mode (as in the exampleabove) to model things like curtains, rice paper, or such effects. In “thin walled” mode itsimply allows the shading of the reverse side of the object to “bleed through”.The shader also operates in “Solid” mode, but the implementation of translucency in themia material is a simplification concerned solely with the transport of light from the back ofan object to it’s front faces and is not “true” SSS (sub surface scattering). An “SSS-like” effectcan be generated by using glossy transparency coupled with translucency but it is neither asfast nor as powerful as the dedicated SSS shaders.