Something like this was already attempted by Luke Parry a long time ago.
He proposed a new Render Project
to define the material properties and appearance of the objects to render inside FreeCAD, and then use Luxrender to produce the final result.
However, that effort didn't really go further. The repository is here https://github.com/mrlukeparry/FreeCAD_ ... raytracing
Though it would take a little to build the libraries for the textures, materials, patterns and such. In the end though, we could end up with one of the most advanced POV-Ray modeling/rendering tools out there. Just a thought...
I'm not sure. I believe POV-Ray already has some GUIs to set up material properties and things like that. See POV-Ray Front End Programs
The Material module of FreeCAD already defines material properties for many different substances. It could be extended with information specific to Blender's Principled BSDF shader, so if the FreeCAD file is opened in Blender it would automatically include sensible presets to render those materials.
This sounds to me like the best workflow. If the user would like to render a good scene, he or she shouldn't mess with text files in POV-Ray, just import the scene into Blender and use the node editor there; see Tutorial Render with Blender
In Blender there is a plugin to import FreeCAD files, written by our very own Yorik; see Tutorial Render with Blender#Importing_plugin
Also, there is apparently a new Render Workbench
that can be installed from the Addon Manager
, which could be extended to use Blender's renderers (EEVEE and Cyles). So, I don't think putting too much effort into POV-Ray is absolutely necessary, as the FreeCAD+Blender combination is probably better in every aspect.