Hi guys, I'm a new Terragen user and loving the exploration into computer generated terrains.
I have come to a crux in figuring out how to input formulas into the shaders or generators. 
For example how would I generate the below island with the Mandelbrot formula z_{n+1} = z_n^2 + c ? 
Would it be possible to somehow create the terrain externally and import? Any help would be greatly appreciated.