In Cycles, the Geometry node has a socket for Parametric. What would this input be useful for?
It looks to me to be identical to UV coordinates for each triangle where the vertices are (0,0),(0,1),(1,0) but with no means of indicating or influencing the orientation of the face. I can't find any meningful documentation that explains what it could be used for.
Can anyone plese explain what it can be used for and, if possible, provide examples of it in use.