War for the Planet of the Apes will hit Chinese mainland theaters on Sept 15. [Photo provided to China Daily]

As the major characters in War for the Planet of the Apes are chimpanzees, artists of Weta Digital researched the animals' physical characteristics, moves and behavior. They used X-ray photos of some chimpanzees to get details about their skeleton and learn about their skin textures.

With nearly 1,000 people from Weta involved in the movie, the majority of the film was shot with visual effects. For the most complicated parts, more than 400 artists worked at the same time.

The hair on an ape's body was processed by software to ensure that changes in the environment, such as snow or bonfire light, are shown on the skin.

"In this film, we see Caesar go from just being a leader to people into being a legend in the ape world. So the film takes on a much grander scope because it becomes sort of an epic mythical journey," says Langlands.

One of his favorite characters is Bad Ape, an intelligent quiet chimpanzee who fled from a zoo.

"Bad Ape is such a different character ... He is so charming and he brings (out) very human and very innocent, curious qualities that the audience can identify with," he says.

"When all of your main characters in the movie are digital, it requires a very close collaboration between the director and the visual effects people to bring that to life."