Animating displacement maps

Boban

I will post here too , because i think is more active forum:D

I watched Blizzard, Making of Reaper of Souls. They did a technique like, animating displacement map for more facial expression or detail animation
[ame="http://www.youtube.com/watch?v=f7zY6MVyAFo"]Blizzcon 2013 - Diablo III Reaper of Souls Cinematic Intro Bringing Death to Life - YouTube[/ame]

It starts from 20:40.

How it is done? Is it hard?

BARDLER

Looks like they hooked it up to the corrective blend shape system. When the rig transitions into a blend shape it also blends into the new displacement map that goes along with it.