With this option the surface_type is selected. This option can be used with albedo_library in order to select a spectral albedo or with rpv_library in order to select a BRDF function.
surface_type surface_type_number
where surface_type_number is an integer starting from 0, where 0 refers to a black surface and the following numbers to the entries in the specified library.





Arve Kylling 2010-03-10