In this image, we see our ape "teenagers" (L-R) Anaya, Noa and Soona. Best friends since birth, they find themselves late in the film on a mission to save their clan from the self-proclaimed king, who sees himself as the second coming of Caesar. The film was photographed in and around Sydney, Australia - predominantly in outdoor locations - depicting a southern California many generations after the events depicted in War for the Planet of the Apes.
This scene was photographed in a dilapidated classroom set at Disney Studios Sydney, with actors Travis, Owen and Lydia flipping through ancient, moldy children’s books by torchlight. Within these pages, they learn the truth about the history of the relationship between apes and humans, and that things weren't always as they are now.
The apes and torch are a digital visual effect. The rest of the image - the book they're holding, adjacent set dressing, the smoked-up set - is real. To achieve this blend, our actors are each wearing active motion-capture suits with facial-capture cameras attached to their helmets. The former has infrared LED lights at key points on their suits, which are recorded by an array of special cameras placed around the set. The latter is a pair of tiny machine vision cameras on the end of a lightweight boom, which records each actor's face 48 frames per second.
Once the collected data is processed back at Wētā FX, we can reconstruct each actor's body and facial movements, and remap those movements onto their ape character. This process is a blend of technology and artistry, with human animators making choices on how those movements are translated. The actors' choices on the day are our ground truth. They provide the soul of these characters, and it is our job to ensure that their ape performance provides the same emotional response from an audience that they did.
Everything that follows the animation - the removal of those actors from the photography; the way their hair is affected by wind or contact with each other; the specific fine details of their skin, hair and eyes; the way the torch light shapes them in the room; the replicating of specific lens characteristics that we can observe in the photography - these are all aspects that the various artists at Wētā contribute to the final result you see in the finished image.
And let's not forget the torch fire. On-set, the actors were holding prop torches, which had a densly-packed array of flickering LED lights, which the gaffer and his team could control wirelessly via a tablet. We weren't able to use real gas flame in many of our interior sets and locations for safety concerns. So, our FX artists at Wētā needed to provide the fire for these scenes via complex flame simulations. We had reference from our shoot, as well as reference that we shot ourselves in Wellington that we constantly referred to, refining the simulation until it very closely replicated the look of the real thing. Once integrated into the live-action photography, the result is a very convincing marriage of digital and practical.
Erik Winquist is a VFX supervisor at Wētā FX (www.wetafx.co.nz) in New Zealand.