Thanks for the suggestions. That's definitely something to consider. I've not used Substance Designer much, so I may have to practise that method in my own time at some point. I've also yet to try Houdini too.
You could generate something similar to these sorts of patterns procedurally. Andrei Zelenco is the master at doing this in substance designer - you can see some examples on his artstation here: https://www.artstation.com/artwork/g2oq8Q you could also look into doing it in houdini. Using something similar to this:…