After the animatic was cut together and agreed the actors were brought back to the AUT motion capture (mocap) studio to capture performances of just the sections of the interviews that had made the cut. Mocap is a technique that uses multiple cameras to capture coloured dot markers strategically stuck to the actor, visually capturing naturalistic movement that is then imposed by computer onto digital characters.
In this case, thanks to the work of designer Colin Wilson, the digital characters were constructed and visualised from the actual historical photographs of the individuals. “The actors brought so much to it – it was wonderful,” says Pooley. “If we’d tried to add that through animation, I don’t know if it would have felt as truthful.”
25 April was the first feature in the world to use Vicon’s Cara for its facial mocap work. The software was also used for Star Wars: the Force Awakens.
If you watch a mocap demonstration, you will see on the computer a wire skeleton mimicking the movements of the actor in real time. But it is never that simple, and the data produced in the mocap sessions has to have detail such as eye movement added, and be cleaned up, as the computer sometimes misinterprets what it sees.
“You always have to massage mocap,” says one of the animation directors, Ray McGrath of Flux Animation. “I have a love hate relationship with it. If I was going to animate a soldier in a real-world situation like this as if I was animating Mickey Mouse, the soldier would look ridiculous. The same thing happens the other way with realistic mocap movement in the wrong context.”
2D 3D mix
Aside from mocap, there is a mixture of hand-drawn 2D backgrounds and 3D animation in the film. It was a practical and economic solution, but also a challenge. Flux did much of the 2D work in Toon Boom Harmony, which the company has been using for several years on its TV shows, including Wiki the Kiwi and the animated elements of Tiki Tour. Maya was used for the 3D work, with the compositing done in Adobe After Effects.
“It is quite a complicated process to marry the 2D and 3D and have them feel like they work,” says McGrath. “It became a hybrid of techniques learned from traditional animation, which we tried to bring into a more modern context. One example is a flyover that I had to create with a raven motif.
“One of the things about animation that you can’t do with live-action, is that it is a lot easier metaphorically, or in a visual sense, to get inside someone’s head. You can actually break away into these kind of artistic surreal moments. Because the world is already animated, it is not such a big transition to the way people are thinking. That way you can start to marry creative visual metaphors.”