Surface roughness. Specifies the relative glossiness of the material surface. Used in conjunction with catalog::Type and catalog::Gloss to control 3D reflection render effects.
Integer number. Percentage value in the range 0…100. Optional for all materials. Used only for vignettes with multiple reflection maps or vignettes with 3D reflection capability. Leave empty or set to -1 if not known or not needed.
-1; a server default is used.