model
Simple Dirty Glass
Get this modelIn case you need to produce a not so premium render. High poly model with subdivision surface modifier. The modifier is not applied and can be removed. Without modifier the low-poly is 1.7 vertices (3.4 tris). With the modifier set to 2 subdivisions--~27.6 vertices (55.2 tris). UV unwrapped, UVs non-overlapping. Glass shader uses dirt mask that is not procedural (included in the file). The intencity if dirt can be adjusted. Feel free to use your own materials if need be.