I don't know about the snarkpit tutorial, but it's defintiely possible, done many different ways.
Try
this one by pepper. If pepper doesn't respond to this thread, try PMing him for hints (I don't think his map explains how they're made).
If that method doesn't work for you, you could make the whole thing out of
displacement structures or as most people refer to it, out of
triangles.
That is, you can make a cube out of 6, 4-side spikes or "triangles", and using these and probably some wedges--made from 3, 4-sided spikes--too. Using this method, you can make virtually any structure with zero errors.
When you're done, NULL the whole structure, and only texture the visible faces. (otherwise, you have some of the faces underneath will show
ugily.