Empire got a chance to talk with Weta senior visual effects supervisor Joe Leterri.
Here's what he had to say:
"The main thing we're trying to do is create these completely believable ape characters and treat them completely in a live-action sense, This actually grew most directly out of what we were doing on Avatar, but here we brought the motion capture completely onto the live-action stage. We had to hide all of the motion-capture cameras all over the live-action sets. And so we could have Andy Serkis, and any of the other actors playing the apes in the set with the [non-ape] actors actually performing."
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