How Weta Created a Post-Apocalyptic London in 'Mortal Engines'

THR - Peter Jackson -Mortal Engines 1 - EMBED 2- 2018
Courtesy of Universal Pictures

Shot nearly entirely on greenscreen, Mortal Engines is based on the YA novel by Philip Reeve and imagines a futuristic steampunk world in which giant mechanical cities on wheels do battle.

Set in a post-apocalyptic world where London — now a giant, predator city on wheels — devours everything in its path, Universal's Mortal Engines may look like it was set thousands of years in the future, but it was crafted entirely in New Zealand, mostly around Wellington, the home of the island country’s most famous filmmaker, Peter Jackson.

Jackson was a writer and producer of the film, opening Dec. 14 and based on the Philip Reeve book series. Directed by Christian Rivers (also a VFX pro who won an Oscar for Jackson’s King Kong), the live action was shot largely on stages at Stone Street Studios and Avalon Studios, both in Wellington, along with some location work in the area.

Jackson's Weta Digital was responsible for world building with extensive visual effects — 1,682 VFX shots, of which 378 were fully CG. Weta sister companies including Stone Street Studios and Park Road Post (which housed postproduction including editing, color grading and sound mixing) all contributing to the final film. VFX producer Andy Taylor says the proximity streamlined production and "we were able to engage with the filmmakers a lot easier."

The overall goal of the VFX was to get as much in camera as possible. "It minimizes the amount of work we do in post and provides the foundation for the world," McGaugh says. "Because it had to be a synthetic, virtual environment, the focus became on putting as much of the human aspects — the set pieces — in camera, and then extending it with virtual worlds." That effectively means that the actors and their immediate surroundings (i.e., the ground they are standing on, or the cockpit in which they are traveling) are real and everything else is CG."

And then there’s a key character, Shrike — part human and part machine — who is hand animated, inspired by the on-set performance of Stephen Lang, who also provided his voice. McGaugh related that Rivers was "very keen that Shrike was mechanical enough so that you couldn’t have a human perform the way he moves, so from the beginning we knew we weren’t going to be able to rely on performance capture or a person in a suit."

But Shrike’s design evolved during production. He adds, "In the visual design he had no skin on his face, but the emotional requirements of his performance did require that we had to add some skin. He went through a redesign and we had to add facial features that we could use in our animation to convey the emotional beats."

Perhaps the biggest challenge — quite literally — was London, which was estimated to weigh 50 million tons and cover 686 million cubic meters, while traveling at 300 kilometers per hour. The CG setting combined many elements of England’s capital city, highlighted by the remains of St. Paul’s dome. "It was tiered to mirror the social hierarchy, with the more affluent sections at the top," McGaugh says, adding that "London’s defining characteristic is the juxtaposition of different styles and eras and architectural tastes." To create this look, VFX worked closely with Oscar-winning production designer Dan Hennah (The Lord of the Rings: The Return of the King) and his team.

New software also had to be developed to meet this goal. "The software we use for building large urban environments assumes the environments aren’t moving, and the tools and workflows for animating vehicles assumes there isn’t anything big or complex on the vehicle," McGaugh explains, noting that in each case, they had to bridge the gaps.

(Mortal Engines is produced by MRC. MRC is a division of Valence Media, which also owns The Hollywood Reporter.)