When making images I may use something I draw/paint from scratch, objects and landscape modeled and rendered with 3D software, or photographs I have taken – sometimes I make use of all three in one image – whatever works. I do a lot of experimentation. In this doodle of stark, high mountains I am trying to “automate” the irregular presence of snow rendered in 3D; so that the snow line is not just that, a line. I haven’t perfected the process, but I think I am on the right track.
In this case I applied a terrain image map which I made in the PD Artist version of Project Dogwaffle (which, by the way, has a very useful 3D terrain modeling filter) to mountainous terrain in Daz Bryce. I duplicated the terrain with a snow material. Repeatedly applying a variety of random variations (noise) in the geometry of the two terrains gave the effect I was looking for. A bit of post-processing produced a rather nice result.