'1917': Inside the War Drama's Seamless VFX Stitchery

1917_20_Still - Publicity - H 2019
Universal Pictures

While Universal's 1917 may not seem like a visual-effects-heavy movie, director Sam Mendes' decision to make his World War I epic appear as a single, uninterrupted shot created a considerable challenge for the Oscar-nominated VFX team that had to invisibly stitch together individual takes. What amounts to unseen work was so extensive that visual effects supervisor Guillaume Rocheron estimates that 91 percent of the final film was touched by the effects team.

Collaboration was critical and began in preproduction, and execution of filming and postproduction came down to meticulous planning by Mendes, cinematographer Roger Deakins and other members of the filmmaking team. Numerous approaches were applied to connecting takes, including wipes at, for instance, a tree or a building; morphing on close-ups of an actor; replacing part of a shot with a computer-generated element; and creating fully digital shots to join one take with the next.

For Rocheron, one of the most challenging portions of the film is a sequence in which Lance Cpl. Schofield (George MacKay), after running through a destroyed city (a location at Shepperton Studios), jumps off a bridge into a river. The leap into the river is fully CG, including a digital double of the actor. It then picks up with the actual MacKay in the water — filmed in a water park that also underwent its own technical manipulations. "It gave us a wonderful base to put the actor in the water, but we had to extend the water digitally to make the river wider and then create the whole environment," Rocheron says, adding that as the actor floats down the river, there are additional stitches of individual takes. The full sequence includes "some of the hardest stitching in the movie."

Another tricky sequence for the VFX team, working out of the Technicolor-owned MPC's Montreal, London and Bangalore facilities, was when Schofield and Lance Cpl. Blake (Dean-Charles Chapman) cross No Man's Land, which was filmed on location in the U.K.'s Salisbury Plain. "We replaced and created a lot of the environment because there was no way to build a No Man's Land up to the horizon," Rocheron explains. "No Man's Land is a vast area that was desolated. There were no trees left, there was nothing that had life that the eye could see." Fog and mist were added to enhance the ambience.

"There was a stitch in No Man's Land that really kept me up at night," Rocheron admits, citing a moment when Schofield and Blake hide in a sub-trench and then walk out onto the open field. "Inside the trench, Roger [shot] the actors on a Technocrane so that the move would be really smooth. But the terrain had to be shot with the Trinity rig to follow the actors for a long period of time on the open terrain. So we did a transition from one camera rig to the other. This transition was hard because it was really slow and you really have time to see it. We went from a fully digital shot in the middle to make the transition completely seamless. It's all about the details."

Those details, of course, only work if they go unnoticed. "If anything looks like a transition, you are giving away the magic trick behind the movie," Rocheron says. "Our job is well done if the viewer never questions it."

This story first appeared in a January stand-alone issue of The Hollywood Reporter magazine. Click here to subscribe.