A variation of this laboriously slow process was used in "King Kong" and then in "Avatar," which used both body performance capture and facial performance capture.
Now, the evolution of visual effects has taken a leap forward.
"Now it's just Andy acting," Letteri said. "It's just the pure performance. We can concentrate on exactly what his face is doing, what his body is doing, and then afterwards we turn that into Caesar."
Performance capture didn't just make it possible for a talented actor to play an ape. For Fox Studios, performance capture technology meant making "Rise of the Planet of the Apes" would be possible.
"This was a great script that we had for a number of years at the studio that we loved from the first minute that we read it," said Tom Rothman, chairman of Fox Studios. "But we didn't have to worry about it, because we knew it couldn't be made.
"It wasn't possible to do because it was a 'Planet of the Apes' from the ape's point of view," he added. "You couldn't [make it] -- unless you know of some very talented apes out there!"