Thanks everyone!
Didn't have much time for further experimentation, so I just shot a few renders with the existing shaders on some random tower structures.
Also a question:
I know it comes up frequently, but what's the reason behind not having different types of voronoi noises in terragen yet? Like manhattan, f1-f2, Chebyshev. I saw them in different programs, and they're probably 3d noises, so is there a problem implementing these in terragen? Or you have to pay for the use of these equations in a software?