Let's face it, even movie star chimpanzees kind of look the same to most humans.
That was a problem that arose in the primate-dominated Dawn of the Planet of the Apes.
"It occurred to us that the viewer might not be able to differentiate between the apes," director Matt Reeves says. "In a normal movie, you would just cast an actor, and everyone would recognize that actor. But this was a big challenge for us."
The solution: Highlight physical signs that would allow viewers to mark each character. For example, new main chimp Blue Eyes gets into a bear fight that leaves his face and body clearly scarred.
"That bear scratch got pretty darn big," Reeves says. "These were the little details we had to work through."
A GUIDE TO THE MAIN APES
Caesar: The highly evolved alpha ape (played by Andy Serkis) returns from 2011's Rise of the Planet of the Apes older and burlier. Reeves says the Weta Digital artists made Caesar slightly more apelike in this film to fit into the concept of a pure ape civilization.
But, along with a lighter complexion, Serkis' humanlike features still shine through.
"You can actually see a bit of (Serkis') face somewhere deep in Caesar's face," Reeves says.
Koba: Caesar's lieutenant carries the source of his human hatred on his face. His scarred left eye has lost pigmentation, and other clear facial marks "reflect the animal testing" the former lab chimpanzee has endured, Reeves says.
Filmmakers even added a scar on his arm to show how Koba (Toby Kebbell) was abused and tortured in a powerful way.
Blue Eyes: Caesar's son (Nick Thurston) has unusual blue primate eyes. There are also obvious marks on his right cheek and right arm from the on-screen bear scrap.
"The bear slashes him across his face and chest," Reeves says. "Those scars and marks remain with him for the rest of the film."
Rocket: Besides having a gray complexion, Rocket is the most powerful-looking of the apes. "He's an ex-circus chimp, and he's super-hyper-strong," says Terry Notary, who plays Rocket. "That's his thing."
He also has a mad arm swing "that is his signature. It's the primal Rocket release valve."
Cornelia: Caesar's wife has more feminine features, which are accented by a floral crown meant to make her stand out. She also keeps "the expressive eyes" of actress Judy Greer, who portrays the new character, Reeves says.
Maurice: The literate orangutan is clear in a world of chimpanzees. Maurice also stands out because of Karin Konoval's motion-capture performance and the Weta Digital depiction, "which represents the highest level of realism in the movie," Reeves says.