In Matt Reeves' War for the Planet of the Apes, audiences meet a chimpanzee called Bad Ape, played by Steve Zahn, who has been living in solitude after he escapes from a zoo, where the humans had scolded him, calling him a "bad ape." The film marks Zahn’s first appearance in the Apes saga as he joined the existing cast, including Andy Serkis, who plays ape leader Caesar, and it was also his first experience with performance capture.

All of that made him nervous when he shot his first scene, which was set in an abandoned building where he meets Caesar and the apes for the first time. "Matt wanted that, because that’s the first thing you see of Bad Ape," he recalls of why that was his first scene filmed during the production. "I remember walking in and seeing that set — an elaborate set with all that snow and chandeliers and three stories. I thought, I had to be really good, right away, and with guys who were on their third movie and had this down. I gained more confidence after that because the scene really worked between Andy and me. Andy Serkis is one of the best actors I have ever worked with. He might be the best actor I have ever worked with.

"I loved Bad Ape's vulnerability. He was in solitude for so long and was yearning for companionship. Within the story, I thought that was so brilliant and would add levity," he says. "Bad Ape’s also a Dad and he’s alone. And he’s dealt with his pain through hoarding." 

As for his introduction to performance capture, Zahn says he learned that acting is no different. “If you had asked me about performance capture before I got to know this process, I would have thought there would be things that would impede the way I usually work,” he admits. “But there isn’t any.

“That’s what scared me,” he adds. “Not only would I have to be believable as a character most importantly, but also you have to believe me as a chimpanzee. I knew playing a chimpanzee would need to be second nature, physically, so that I could get to a point where I could just play a character.

“There's a lot of technology but it doesn’t impede you on set,” he continues. “The Weta people get really excited when they are watching the monitors and see two people in grey outfits with dots on their face makes them want to cry. That's when they come up and say ‘this scene is going to be great.’ They are reacting in the same way as an audience."

Of the larger story of the apes versus the humans, fighting for their civilizations, Zahn says, “This is so relevant to today: The dangers of fear. The lack of empathy. This general lack of not understanding others who are not like you. A changing world — maybe changing a little faster than we think it is.