Help needed for creating broken glass effect (in Cycles)

Hello there.

I have created a nice grungy glass material, using the technique from one of the tutorials on Blender Guru. The node set up is pretty much the same as the one in the tutorial.

I’d like to add a broken glass texture to it such as one of the following from CG Textures (or something similar). What I need to know is how to set it up, I’d like to do it in such a way that the hole in the glass does not show the grungy texture of the glass but allows the background to show through clearly.

If anyone can give me some pointers I’d be extremely grateful.

Thanks

Depending on how accurate you want it to look - you’d may be better modelling it using cell fracture and grease pencil using a technique similar to that used in this tutorial.

Nice one, that is the effect I’m going for. Seems to have got something along the lines of what I’m looking for already, just need to play around with it and tweak it a bit