Polygon Optical Prism Objects are one way of creating flexible user-defined volumes or shells within OpticStudio.
Assigning surfaces of the Polygon Object to different face groups
Each face generated in the POB file can be assigned a unique face group, or perhaps one which is common to other faces of the object. This way, the user has the flexibility of defining different coating and scattering properties to different faces of the faceted object.
Reference Source: https://www.zemax.com/
