1917: One Shot Wonder
TREVOR HOGG GOES DOWN INTO THE TRENCHES WITH GUILLAUME ROCHERON TO LEARN ABOUT THE OSCARWINNING VISUAL EFFECTS OF 1917
Go behind the scenes of the Oscar-winning VFX of 1917
“IT WAS CRITICAL THAT WHATEVER WE DID TO ASSEMBLE AND CONNECT THE SHOTS TOGETHER NEVER BETRAYED THE CAMERA WORK”
Guillaume Rocheron, production VFX supervisor
In order to honour the stories told by his grandfather about being a soldier during World War I and immerse the audience in the experience, filmmaker Sam Mendes (Skyfall) decided to follow the mission of British lance corporals Tom Blake (Deancharles Chapman) and William Schofield (George Mackay) to call off an attack through war-torn France as if it was a single shot. The concept led to a rethinking of the traditional way of tackling visual effects, which are normally divided by shots and sequences. The postproduction period for 1917 lasted 17 weeks with digital augmented imagery encompassing 91 per cent of the theatrical runtime.
“Visual effects pipelines are not good at handling shots that are over 500 frames, which is a 20-second shot,” notes production VFX supervisor Guillaume Rocheron (Ghost In The Shell). “On this movie we had some takes that were seven minutes long and others that were a couple of seconds. One thing that we realised quickly is that shots can’t be defined by cutting from one to the other because the shot count becomes too long, but also when the shot goes to the next one, we have to work to connect them.”
With the continuous shot approach making dividing the workload tricky and the methodology of stitching being so specific and precise, the decision was made for MPC to be the sole visual effects vendor on the project. “It required a lot of planning from MPC just to logistically handle the movie, because how do you design, split and review the work?”
A close collaboration was had with cinematographer Roger Deakins (Blade Runner 2049) and editor Lee Smith (Dunkirk). “With the stitching, it was critical that whatever we did to assemble and connect the shots together never betrayed the camera work, especially when you get someone like Roger Deakins who is a master of what he does,” notes Rocheron. “One of the creative challenges on this movie from a visual effects standpoint was, how do you make it absolutely invisible and make sure that the camera flows from shot to shot? I worked closely with Lee Smith who looked at the performances and the different takes. He would want to stitch some of them together. That is a trade you make. Do you go for the right performance or the flow of the movie? Credit to Sam Mendes, because as director he constantly had that choice to make.”
Most of the action takes place in exterior settings. “Dealing with uncontrolled environments makes it really hard by default,” remarks Rocheron. “It’s much easier on land when you have foreground objects or architecture which allows you to go around the corner or go into a room and have a drastic change in environment. However, with 1917, it’s a journey that starts from A and goes to B and never stops. You never have a repeating environment or much to help you with blending things together. A lot of the stitches are in plain sight where you are close-up on a character or there is a bit of a camera move. We do very few transitions behind trees or objects because it starts to become too obvious if you start to do that systematically. I’ve been asked if
there was a piece of tech that we wrote to handle all of the stitches, but that was not possible as there wasn’t one solution. Some shots we transitioned to a CG camera or a digital double or did morphing/ warping or 2.5D projections, or sometimes it was simpler. We had to study every transition and design a solution for each one of them.”
Mud has a dominant presence. “When they cross No Man’s Land, production designer Dennis Gassner [The Truman Show] had created a large mud field with craters, but we needed to extend it all of the way to the horizon,” states Rocheron. “The scene is seven minutes long and you are following our characters with minimal foreground stuff to help with transitions as it is an open field. We did seven stitches for the whole sequence with constant set extensions. There was always
“WE DO VERY FEW TRANSITIONS BEHIND TREES OR OBJECTS BECAUSE IT BECOMES TOO OBVIOUS IF YOU DO THAT SYSTEMATICALLY” Guillaume Rocheron, production VFX supervisor
a stitch for a reason. It’s either because the first shot of the day has to be stitched with the last shot of the day before. You plan it in your shoot schedule. Or it’s because we have to transition to a different set or location. Sometimes we did it to transition from a different camera rig. In order to push in on the characters when they’re in the trench, Roger went with a Technocrane. As they get out of the trench, we’re now on an ARRI Trinity Rig [five-axis hybrid camera stabiliser]. You follow them for two minutes on rough terrain without any interruption. The transition was done with digital doubles and a 2.5D reprojection of the environment. The secret with stitching is that you always have to be on the move and fluid.”
Flares were fired during the nighttime scene in the bombed-out French village of Écoust-saint-mein, which was a massive physical set build. “It was complicated for the stitching and set extensions because you’re dealing with lights that are
“THE EXPLOSIONS WERE A COMBINATION OF PRACTICAL EFFECTS AND ELEMENTS THAT WERE DIGITALLY ADDED”
constantly moving,” remarks Rocheron. “The most interesting thing was how the scene was lit. They were magnesium flares that were engineered by special effects supervisor Dominic Tuohy [Solo: A Star Wars Story]. The path of every flare was precisely designed. Sam had requested that the flares burn and travel 130 feet in 22 seconds to create a certain artistic choreography. Roger also wanted the flares to be a specific colour for his lighting. It’s not just about creating a lot of light, but the light also has to be picture friendly. It was one of the first times that I saw a special effects rig be the sole light source for an entire scene. That was really cool and effective.”
Schofield takes a shortcut across a battlefield while hundreds of soldiers are charging forward and artillery explosions are going off around him. “That was an interesting moment to work on because the explosions were a combination of practical effects and elements that were digitally added. From a special effects standpoint, it was freaky because you have 500 extras running on the field, the camera is on the back of a jeep driving at full speed, our character is running and all of the explosions have to be triggered. We did some stitching in there. The whole concept of the shot is that the battlefield they are going to fight on is intact. It is going to become like No Man’s Land, but there are still flowers on the ground. In order to remove the jeep and the giant holes for the big explosions, the whole terrain had to be replaced digitally to get something clean and pristine. It was better to get the explosions and the grit of the pyro in there rather than keep the ground completely clean.”
“The big effect that we didn’t manage to shoot any reference for was the burning church,” reveals Rocheron. “That had to be completely CG because of the scale of it. Roger had a large bed of lights to create a lot of light and contrast with the characters. Then what we did was to rotoscope against it,
scanned a church which was rebuilt in CG, ran it through the stages of destruction, put it in the shot, and inside added fire, collapsing beams, and embers to create a raging inferno.” The art stitching resembles a magic trick. “What I really like on the film is the stitches are where you don’t think they are. We did that because those are the places where maybe you will not look; that’s how we got them to be invisible.”
BIG BLACK RATS
CG creatures needed to be produced for 1917, in particular black rats. “In terms of the fur shading it was complicated because you have little textural information to give them,” observes Rocheron. “It’s all about how the light hits them and the reflections. From a lighting standpoint we had to be subtle. When they’re in the German dugout we had to do a more subdued animation. Showing the movie to a few people, we got a laugh when one of characters says, ‘Their rats are bigger than ours.’ The rats were fairly high resolution. We’re using them multiple times in the movie, like in No Man’s Land. It was more about the groom and fur than the model. They had to be mingy, oily and irregular.”
ESCAPE FROM ÉCOUST-SAINT-MEIN
While being hunted by German soldiers in Écoust-saint-mein,
British lance corporal William Schofield (George Mackay) jumps off a bridge into a river. “When Schofield runs out of the burning village at night, that was captured at Shepperton Studios, and the river was shot at the Lee Valley White Water Centre, which was a facility built for the London 2012 Summer Olympics,” reveals Rocheron. “You get the water but it’s in concrete walls. We went there because they have a high flow rate of water. The stitching for the river sequence was immensely complicated because you’re dealing with character and an environment that is changing every frame. When dealing with water you have to transition splashes and white water which are constantly moving. We solved that by doing some warping and morphing as well as creating patches of CG water and spray.”
Schofield goes over a waterfall, and “we had to make it look dangerous but not remarkable,” explains Rocheron. “1917 is not a superhero film. For that section, we went completely with digital water in order to control the look and size of the waterfall. We also used a digital double because the most important thing was to have shots flow into each other. We also did a full digital shot when Schofield jumps into the water because it was the only way the moment could be filmed in a believable manner. Originally, we were going to use a different methodology and utilise a Cablecam on a descender rig, but I realised that wasn’t going to work artistically because you’re betraying the camera work, as it looks like the camera has been preprogrammed. The CG approach let us really animate the camera like an operator was jumping off the bridge and was trying to keep Schofield in the frame.”
GERMAN PLANE CRASH
Traditional editing techniques of cutting back and forth between reaction shots were not used when the German Albatros plane crashes. “The plane crash is one of my favourite scenes because it encapsulates the philosophy of the movie quite well in terms of the visual effects work,” notes Rocheron. “A German Albatros is