Scratched Glass - How to - need some big help

[Campione]

Hey all,

So i have a question that seems so easy but is killing me to solve. How do I do scratched glass like you'd see on old glasses or goggles using the architectural shader. I made a scratch map in PS with an alpha and mapped that to the color port of a mix 2 colors and then multiplied by the alpha and I get nothing showing up as scratches just the clear arch material.

This is an HDRI lit scene with FG and 2 diffuse bounces[img]

heres my render tree

[/img]

Somebody please help.

[Pancho]

Your using the diffuse input. Why? How does a diffuse channel alter an almost transparent object? Almost not at all!

Use a bump map node and use your image in the specular and glossiness channels. THen you should see a difference.