been a while since I have been on here. Have not found a whole lot on wireframe rendering in Maya. So I played around with it and found a nice trick on how to put a wireframe on a poly or subd. This will be done with vray for maya.
Unlike MR or MayaVector, the "wireframe pass" (lets call it that for simplicity) is done before the actual render and not as a post-effect. The scene I am using for this is the simplest there can be - 2 spheres on left hand side poly, on right hand side subd lighted by 2 point lights from front. The first picuture with MR shows the inability to wireframe the subd sphere. To see the difference you have to view the full res version (they are each in HD720).
Also note how the wireframe is only one color. Now the exact same render done with Vray:
In Vray the wireframe is part of the color value of the default lambert material. This is how I connected them:
The first VRayEdgeColor is a 2D texture (VRay Edges) with white as Edges Color color, and blue for Background Color and 1.000 Pixels width. This connects VRayEdgeColor.outColor->blendColors.color1. The second node EdgeOutline is also of the type VRay Edges, but this time white edges and black background with 3.000 pixels width. I connected EdgeOutline.outColorR->blendColors1.blender. Does not really matter which color channel you use here. The other color I left the default 50% gray - this however can be linked to any texture. Then last not least, connect [I]blendColors.output->lambert1.color[/]. Now it is ready to render in Vray in a single pass w/o compositing afterwards. This setup also allows to render the same scene with different renderer w/o having to touch hypershade at all - it appears that VRay Edges defaults to the background color if not using Vray. this will blend out the wireframe completely no matter how the colors are set up in VRayEdgeColor.
Now showing WIP can be done w/ wireframe and still correctly lit up (including the wireframe) in a single render pass even with SubD. All you need is save picture from renderview. Only drawback - NURBS still won't be able to render wireframe directly in Vray. NURBS can be rendered with wireframe, but unfortunately it will use the tesselated triangular mesh.
If this is useful (or not) please let me know
p.s.: oh almost forgot - do experiment with it - with the wireframe calculated pre-render new possibilities open up. e.g. wireframe as bump/displacement, 2 sided shading with different color on the backside of the wireframe ....
