Get the look of grimy, dirty old windows automatically with this shader. Renders and videos shown in Eevee. Any object touching the glass will create an adjustable grunge effect around it. The grunge is based on position, so no UV's are required. Check out the demo videos to see how it works. 4 shader variations included, as well as the tiling diamond window object.

This works in Cycles, but I haven't dialed in any of the presets specifically for it. Cycles intensify the effect and spreads it out, so with a little playing you should be able to find something you like.

The sky background is not included. It's Physical Starlight and Atmosphere, available on this site.