To create a common glass material, the Refl 90° color can be left at 255 because this glass will not tint the specular reflections. In addition it will reflect almost all light at this viewing angle.
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Roughness must be set to 0 for a perfectly smooth glass. Increase this value (for example to 20) if you want to get a glossy “frosty” glass
The basic structure of a glass material, smooth (Roughness=0) and frosty (Roughness=20). You can download those material examples here: Smooth Glass and Frosted Glass.
Find more glass examples at the MXM Gallery.
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