I realized the tutorial I was typing out was too long and detailed for something that is a senior project. These are the maps I would use for dirty glass (make sure to UV the glass and output it to photoshop first): 1) Diffuse - Base color of the glass + any dirt/dust 2) Specular - A greyscale version of the diffuse layer,…
Ohh I did forget something 7) Bump/Normal Map - Self explanatory. Dust is probably too thin to influence the bump so don't include it, but thick dirt, scratches, or other surface imperfections you can include. 8) Gloss/Eccentricity Map - Don't really know how to create one of these since I've only ever used the default…
i did some pretty decent glass on warhammer by using a bluish difuse, a cloudy alpha, a splotchy spec map, and an enviroment map of basicaly a photo. took a lot of tweaking on all of it to get it to look right, but in the end it worked