I'm supposed to reproduce these as an exercice. I'm having trouble with two thing on these
> 1st pic
How did he manage to keep the top of the extruded regions flat and valley like? I tried using a mountain noise on a primitive group (selected randomly which also doesn't give the same effect) but it doesn't work, it's extruded on the normals of each primitives which creates a mess of overlapping geometries?
> 2nd pic
Also after the polyextrude, how did he manage to divide the geometry to have cube like formations instead of only have the surface primitive being extruded.

Don't spoil it too much for me, clues and directions are enough.

Sorry if I don't use the correct words of if I'm too vague.