Stacking the same texture sample on top of itself

I have a glass-like surface in my game and I want it to add cracks to it procedurally. So I got this idea to use a normal map with couple of “cracks” → then if the surface takes more damage, I will use the same texture sample, but will add it on top of itself with a rotation (so now there are twice as many cracks) → and then even more layers with a different rotation as damage increases, so that the amount of cracks increases and I use only one texture sample (which is good…?).

The issue is I have no idea how to do this in the material graph. Didn’t have much success with googling either, which might imply there is something wrong with the method itself. Does this make sense? Are there better ways? How do I do this?

Huge thanks in advance! :slight_smile:

Hi!
I would not stack the same texture on top on itself, but I would instead change the visibility with the help of a mask and a Material Parameter Collection that controls how much of the cracks that should be visible. This Material Parameter can be set in a blueprint so the cracks can be updated over time.

Thank you for the reply! I don’t think a mask will work in this case because the pieces of glass have different “angle” in the normal map. So if I hide/reveal a portion of the map, it doesn’t have the same effect as two of them on top each other.

here is an example of a mesh I would use as basis for generating the normal map: