1. 
   I just watched the video for Vector Displacement again. Really exciting stuff but I cant grasp what's actually going on.

How come the displacement map makes the shape go up, outwards, inwards and then outwards again. I understand how an Image displacement map ordinarily makes the  (for instance) landmass go upwards and inwards conically.....

But this is a peculiarity. What actually allows parts of the object to shrink and then expand again at given points? Not just an image, surely.

Armstrong.