I'm trying to create a scene which contains text "painted" onto a wall. I want the paint to appear a little chipped/eroded. I've experimented with the transparency channel and noise filters but I can't quite get it right. As you can see in below, the "chipped" area isn't completely transparent, you can still make out the edge of the text. Could anyone help?
you have Specular on which hasn't been told to not produce specular highlights where the the transparency is... either use an inverse of the same noise in the Specular channel or just use the Alpha channel rather than the Transparency because the Alpha knows to automatically disable specular wherever there is a 'hole'.