I wonder how much work would it entail to swap one actor's face for another's in a movie. Just finished watching Fury Road, and Tom Hardy just feels a bit off to me.
That's "bread and butter" work in VFX. I used to be a stunt double actor replacement specialist. These daze, ML enhanced tools make the work for a face replacement shot exponentially faster and easier - as is needed for the huge number of superhero stunts insurance companies will not let the stars perform.
Each film he does one very public stunt for real; for the other stunt shots he does them as well, but not hanging off the side of a building or whatever, he's 5 inches off the ground with a landing pad in case someone slips. Remember that whatever is in the background was probably not there when the sequence was shot; background replacement is another "bread and butter" effect.
