per-face color shader

[mHennessy]

i am using Maya 2012 sp2 and i am trying to better visualize the MR subdivision approximation editor settings.

what i was trying to do is make a shader that when rendered assigned a random color per face so that i can see where and how dense the subdivisions are after MR subdivision.

for instance i have two nurbs surfaces that that share an edge. I am trying to get MR to tessellate but i would like to fine tune the amount of triangles that MR generates to render the surface so that the two edges render without gaps due to uneven amounts of tris along that edge. I am unable to change the surface parameters directly as the nurbs are from CAD and approved by client as is.

I am hoping someone has done this already and can point me in the right direction.
also i hope that there is a way to do this using standard Maya MR nodes and not writing a new shader plugin (maybe using an expression?)

[bart]

To do exactly what you want, you'd need at least a shader that got the id of a given poly. You could use that for some kind of color lookup, perhaps. But I'm not sure that the Maya Sampler Info has that.

Do you know about using Contour Shaders with the option Draw By Property Difference .. Around Render Tessellation?