@kammutierspule
here there is a fully Open Hardware KiCad project that @Anool did at Hackaday with all STEP and VRML models coming from @Anool, @Joan_Sparky, me and StepUp libraries
https://sourceforge.net/projects/kicadstepup/files/prjs/HACK-master-R3.7z/download
I updated the 3D VRML models adding Material Properties as per your Guide Lines
hack-VRML.7z (272.8 KB)
hack-fused_FreeCAD-016.7z (780.7 KB)
and the MCAD + VRML combination (mechanical model plus VRML aesthetics)
They are not as nicer as @xavierw rendering but at least they are GPL’d and fully shareable … this, IMO, is the only way to have a MCAD collaboration, the only other option is buying STEP libraries around
I hope they could be useful for your rendering tests…
Maurice