you can invert a power fractal terrain maybe even a color fractal by switching buoyancy from variation to a negative number
;D
So do you think that can work for creating Caves and so forth?, please post an image when you do and maybe a screen or 2 of the nodes and settings on how you did it real quick? Now that you got our juices flowing? ROTFL lolol
DT
Sorry but I didn't get a chance to explain much. In the the power fractal go to the tweak noise and under noise variation slide it to -1. I don't think you can do caves in this manner but you can make canyons when used with a terrain are cracks used with a shader if you change the variation too a high number.