Weta’s facial capture builds have brought Andy Serkis’ performance of Kong even further than when he played Gollum in The Lord of the Rings.

To achieve this breakthrough, Weta’s facial capture builds on the program called Facial Animation Coding System (FACS) developed by Paul Ekman at the University of California at San Francisco. “The basic idea is that human muscles can only work in groups that form expressions,” explains senior visual effects supervisor Joe Letteri. “You can reverse engineer that by reading the patterns on someone’s face and figuring out what muscles activate it, pull everything into this pattern by starting with a neutral pose and going from there. Then you can infer what expressions are being made from those groups. But whereas with Gollum we sculpted all the group of expressions by hand, with Kong they were able to codify it by building an underlying muscle system to drive the facial performance instead of having to sculpt it all. And then by using the MoCap techniques on Andy, they were able to figure out what those facial expressions must have been.

“What worked well for that was we were able to figure out a system that could be driven not only by motion capture but also by keyframe animation. So we could go back and forth between the two. But you always got Kong out of the deal. You could keep him on model easily, with room to vary. What was interesting was that we were able to learn what the eyes were doing from the motion capture. You couldn’t track the eyes directly, but it was the same logic because once you figured out what the muscles in the face were doing, you could infer what the eyes were doing from the muscles around them. So we got that from our early tests with motion capture.”

In reality, only about 25% of Kong was performed through facial motion capture, with 125 markers on Serkis’ face. The vast majority was keyframed because of the physical demands of the performance, with Kong running, jumping, climbing and battling dinosaurs. “Even the motion capture work was run through the animators to make sure it was true to character because you don’t want the machine making all the choices for you,” Letteri adds.

Although the Weta Digital team relied again on Maya (along with RenderMan and Shake) for animating Kong and other creatures, the particular demands of creating five million hairs on the gorilla required new hair and fur simulation with processing power comparable to the U.S. military’s, according to Taylor (4,500 processors and 150 terabytes of disk space). Letteri emphasizes that this was necessary for gritty realistic close-ups as well as intense collisions with other characters.

From Skull Island to New York City, Kong is king.