mental ray Architectural and Design Visualization Shader Library

3.4 Common Parameters 633.3 Important Note on Fast SSS and Sun&SkyTo use the mental ray fast SSS shaders together with the high dynamic range indirect sunand skylight, it is very important to turn on the Indirect parameter so the SSS shader canscatter the skylight (which is considered indirect).It is equally important to turn off the Screen composit parameter (otherwise the output ofthe SSS shaders are clamped to a low dynamic range and will appear to render black).3.4 Common ParametersSome parameters exist both in the mia physicalsun and mia physicalsky and all do the samething. For physical correctness, it is necessary to keep these parameter in sync with eachother in both the sun and sky. For example, a sun with a different haze value than the skycannot be guaranteed to be physically plausible.