Occlusion + Facing Ratio?

[MikeVerta]

I need help building an Arnold shader - I have all but the last step, where I want to make the Occlusion-based "Dirt" also subject to FacingRatio so it appears primarily at grazing angles. How can I do this?

So far:

Thank you!

[lee_griggs]

There is a facing ratio shader in MtoA that you could try.

Zeno Pelgrims also has a dirt shader available for MtoA.

[MikeVerta · Accepted solution]

I answered my own question.

The trick was to drive a ramp with a samplerInfo node's Facing Ratio output, and then modify that ramp's color gain with the Ambient Occlusion node.

So, for others:

samplerInfo [Facing Ratio output] > ramp1 [UV Coord input]

then:

ai_AmbientOcclusion [Out Color output] > ramp1 [Color Gain input]

Then take the ramp1 [Out Color output] and connect it to the Mix input of an ai_MixShader. This will use ambient occlusion to place 1 shader on top of another, and also subject it to viewing angle.

[lee_griggs]

Images or it didn't happen 😉