Default value for Specularspike constant

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_Geant4 Version:_11.3.2
_Operating System:_Alma Linux
Compiler/Version:
_CMake Version:_3.2.6

— I had a question about using Geant4’s Unified model for optical surfaces. When the finish is set to, say, ground, there are four available reflection types: specular spike, specular lobe, backscatter, and Lambertian. What are the default values for the corresponding constants? For example, if I only specify the finish as ground and do not set each constant individually, what values will each of these constants have?

For specular spike, specular lobe, and backscatter, the default value is 0.

The default value for Lambertian is 1 - (sum of the other three).