Morphing low poly object to high poly object I have multiple high density head models and one low poly head model. The high-density models are different between each other in details like mouth expression. I'm looking for a most efficient way to make the low poly object as similar as possible to one of the high poly models. 
I'm well aware that there could not be a method that will do it perfectly for any sample high poly model, so I allow it to be succeed by minor fixes by hand.
The first thing that came to my mind was to do simple retopology with snapping. The result would be nice and accurate, but it's made by hand all the way and I'm searching for something batch-like. Is there a way to do it more automatically?
Use the shrinkwrap modifier. First set a Shrinkwrap modifier to the low poly(make sure it is in the same place as the high poly and larger than the high poly) then set the Target to the high poly with settings set to Nearest Surface Point.