Sunday morning here in the Uk and a little bit of node fun. Just playing around trying to see what i can come up with. No plan in mind, just seeing where it takes me.
I know we have a fake stones shader, and this probably isn't much use, but a plane with a voronoi textured, and we kind of get the effect. not sure where it will lead unless you wanted to enter minus values for a cave roof? again you could probably get the same effect with the fake stones, but it doesn't hurt to play around and see what you can do. If any one has any ideas let me know
It's always interesting to experiment a bit. I found out a lot of TG's workings by doing so over the years. Speaking of caves by fake stones; I went there too. Try a really huge one, and you'll get some sort of sinkhole, very interesting stuff.