Metal Material with Edge Definition - How?

[Larissa Holderness]

I have a request to create a champagne aluminum metal that shows the edges of the geometry (the material will be applied to mullions).

 

So far I have tried a VRayBlendMtl - put the Aluminum metal in the Base slot, a VRayMtl with a dark gray in the Coat 1 slot, and Blend 1 has a VRayEdgesTex that is set to white. However, the Coat 1 material (dark gray) is being applied to the entire material and making the 'aluminum' darker. Is there anyway around this - without making the metal material lighter to compensate?

 

See attached image for my material set up

 

Thanks!

[Francisco Penaloza]

did you tried composite shader?

[Larissa Holderness]

I have not. But will give it a go.

[Stephen Thomas]

Is it actually rendering darker or could it just be a visual quirk of the material editor?

[Nicolai Bongard]

If your geometry has lots of edges that it takes into account you may get the edge material on unwanted places. Perhaps you could create intersecting geometry where you want the darker material to be, then use vray Distance tex instead of edges tex to get the darker material only where you want it. An easy way to create the geometry would be to select the edges in edit poly mode, then create splines from them and give them thickness, then just make sure they are hidden in the render?

[Stephen Thomas]

Ok, so it seems all you have to do is set the swatch for blend amount in your coat material to black. This is what is controlling the areas that aren't governed by the edgestex. By default it is mid grey.

[jonseagull]

Yeah, I never understood why that gray is the default. I've never not set it to black.

[beestee]

The edge map works differently when used in a diffuse slot or bump slot.

 

Using the edge map in a bump map slot will round off hard geometry edges so that they will pick up highlights in reflection. Using the edge map in the diffuse slot simply traces all geometric faces with a hard stroke using the chosen color.

 

Using an AO map like Nicolai suggests will probably work better for getting that definition directly from the diffuse color if that is the way it must be done.