How to get the wireframe look with V-Ray?

To render with wireframe effect in V-Ray we need to use  VRayEdgesText.
Just combine the GRAY into diffuse and the BLACK into the VRayEdgesTex map:

Apply to all objects and this is the result:

You can also use the BLUE into diffuse and WHITE for VRayEdgedsTex:

Another creative application is to get some transparent objects!
Just copy the map in the opacity channel – I did this for books and their box:

Note
VRayEdgesText can be also used to smooth corners.
Check: Smooth Edges with VRayEdgeTex