How MPC handled transitions, set-extended war-torn France, orchestrated a plane crash, and turned an Olympic whitewater rafting course into a wild river ride

By now, many people would be familiar with the ‘continuous take’ nature of Sam Mendes Great War tale 1917, which follows two British soldiers – Schofield and Blake – as they attempt to deliver a crucial last-ditch message to another battalion on the battlefield.

The film was, of course, captured via several takes meticulously planned and rehearsed on vast sets (rehearsals lasted 24 weeks) with a myriad camera rigs devised by the director of photography Roger Deakins. Many other members of the crew, including production designer Dennis Gassner and SFX supervisor Dominic Tuohy, also played a hand in devising ‘oners’.

It then became the job of the visual effects team from MPC to stitch certain takes together and provide VFX for key moments in the film, such as a stunning one-take plane crash, a daring river ride, and for many of the movie’s war-torn environments. befores & afters spoke with MPC visual effects supervisor Guillaume Rocheron, who worked closely with fellow MPC visual effects supervisor Greg Butler, to break down five of the key VFX moments in 1917. (Rocheron, Butler and Tuohy have been nominated for the VFX Oscar for the film, too).

1. Stitching: the challenge of transitions

Guillaume Rocheron (visual effects supervisor, MPC): With the stitches, there’s several things we always had to think about. The camera needed to feel very organic, and often that drove the methodology of how we would do a stitch. Whether it was a simple 2D blend, or a morph, or two-and-a-half-D, or going into completely 3D. It really depended on the action, but you never wanted to break the ‘magic trick’.

What was interesting about this movie was that on paper it’s not supposed to be a visual effects movie. It’s not supposed to be a giant spectacle, so anything that distracts you, or anything where you feel the choreography of the actors or the camera isn’t working right away, you’re crossing the line to not being invisible enough. That was a big consideration.

The other very important consideration that made life challenging was that we decided to never try to ‘hide’ the transitions. We never wanted to lose the actors, by saying, ‘Hey, here’s a tree and we’re going to blend when the actor goes behind the tree’. There were some shots where we did kind of do that, but we never lost the actors. If we transitioned behind someone, we always made sure there was an arm of the actor or a leg or the face was always in frame. Sam didn’t want the transitions to feel like they were hiding something because if we did that the audience was going to feel like that’s exactly what we were doing.

We’ve done shots where we transition on close-ups on actor faces. You go from one take to the other because we transitioned set, and then it was a lot of morphing and re-projection. The goal wasn’t to be fancy with the tech but instead to think about ways to make transitions not look like they didn’t belong with the rest of the film.

We would shoot A and B plates – and we had a compositor on set to do a couple of line-ups. We didn’t shoot with any motion control, we just went with a lot of overlaps. When we had to blend between two takes, we really had them overlap their moves as much as possible between the A and B plates, as well as the camera. Then for the few frames of transition, we would really go in and basically do some 2D morphing in Nuke to blend between the two. You would also have to pick moments where the camera is a bit on the move or there’s a slight light change. Or you transition in different stages, say the arm first, or a couple of frames or seconds after you transition something else.

In all the shots, the roto and prep team were the real heroes. We filmed in natural light. We had very few bluescreens. If you look at the No Man’s Land sequence, we shot entirely without bluescreens so absolutely everything is roto’d. VFX touched 91% per cent of the frames of the film. 91% are VFX frames. Most of them are roto. It let us insert or replace or set extend or blend.

DOP Roger Deakins and his team factored in as many practical transitions as possible, and some of them are pretty incredible, where they literally carry a camera and drop it onto a cable-cam and it goes across an area and they pick up the camera again. It is truly mind-blowing. We did rehearsals for the actors, but we also did rehearsals for the camera operators as well. It’s really a dance, and a ballet.

For example, when they enter No Man’s Land and they jump into the trench and we do a transition on the wrap around there to transition from a Trinity rig which is carried by two camera operators to a Technocrane. Because once they’re both in the trench we want to push in behind them, and then as they exit the trench, we want to transition back into a different camera rig so it can be carried across the mud.

2. Making a plane crash

One of my favorite VFX shots ever is the mirror shot in Contact. At some point you realize you’re seeing this action through the mirror. But there’s something about it where it doesn’t distract you. If you don’t really pay attention, you might not even notice it. But when you do it’s like, woah what a wonderful point of view. Also, technically your brain explodes – what!?

What I like about the plane crash is that you’re literally with the characters and then you see the dogfight in the sky and then the plane crashes next to them, and then they end up extracting the pilot from the plane itself and dragging him out. And then the scene that follows has the plane burning behind them for literally five minutes.

It’s a combination of lots of different techniques. When the planes are flying it’s CG and as the plane goes down towards the characters it’s a CG plane, then as it crashes into the barn, there’s some CG destruction but then the plane transitions to a bluescreen special effects plane replica. They built the replica and a small section of the barn and then we just shot elements. We would ramp the plane through a wooden area with fireballs going off, and then it get sets on fire.

The first plate is the actors with no plane whatsoever. Then the plane crashes and in CG we transition to a special effects plane. Then that combination is added to the first plate. Then as the characters stand up to go rescue the pilot, that’s when we transition to a third plate, where on location where the plane is dressed with flames and the pilot in it.

Generally, you do an establisher, a reaction shot etc, and you can make a shot like the plane crash feel very dynamic, simply with editing. But in this case – where we couldn’t do any edits – it was all about the choreography. CG is great for shots that are like 4 seconds. When you have 10 seconds, you know that’s going to be a hard shot. But then when you have a 20 second VFX shot in the movie, it seems like an eternity! It’s a really really complicated shot.

In fact, we had to, for this movie, almost re-think the way we work, and eliminate the concept of shots. You could really only validate that the scene was working by running the whole thing. That’s because the work involved in putting 5,000 frames for review is completely different from normal.

3. Through Écoust

Schofield here crosses a bridge, takes on a sniper, dodges enemy fire and runs through the ruins of Écoust. It includes one of my favorite special effects in the movie as he is running away through the shadows of the ruined buildings, all lit by moving flares. SFX supervisor Dominc Twohy worked closely with Roger Deakins to design an effects rig for flares.

The flares had to go off for 22 seconds and travel 130 feet to really create these big shadows that Roger and Sam were after. They had those bigs things on winches going over the set creating the illumination. I don’t think I’ve seen a special effects rig do the lighting.

The burning church later is a combination of VFX and practical lighting. Roger created big stackable banks of lights. It would pulse at different rates to look like fire. What we did was remove that, roto everything in front of it, and replaced it with a burning church. We found a church in France that we scanned and could simulate to destroy and place some fire on the inside.

The set itself was all built on the backlot at Shepperton Studios, so we did quite a lot of set extension. It’s a large area – all the architecture was there in close proximity to the actor, and then what we did was scan it, and re-created an extended version of the village.

4. River rapids

As Schofield runs towards the water, we had to connect the village to the bridge area he jumps off. So, he’s running along the backlot of Shepperton but the next piece of photography is him shot at the Tees Barrage International Whitewater Centre, a whitewater course that was used for the London Olympics.

We had to design all the surroundings as he’s getting to the bridge; you need to start to see the river and the banks. Here we got into CG shots for the part where he jumps in.

Then when he’s in the water at the water park, we replaced the whole environment. Shooting it in a water park was really about us trying to get control. We needed to be able to put an actor in a safe environment, but at the same time have white water and rushing water. You can’t really shoot it in a tank like you might other water scenes, and you can’t go in a real river because it’s way too dangerous and you can’t really film someone in the water this way.

So we needed Schofield and the water interacting immediately around him. Everything else could be digital. We had to create the environment and all the water that flows with it. It was also hard with stitches. When we get into stitching in the river, now we needed to make sure to blend the actor but also the water and splashes. It was incredibly intricate – we’d take a splash from the first plate, extend it in CG to the second plate so it flowed from one plate to the other so you don’t question it too much. It was probably the most complicated scene.

Sam also wanted the path in the river to feel dangerous, with not only white water but also sharp rocks sticking out. Even if we were in a controlled environment, you don’t really want to take a chance with things that are too dangerous. So the way we did it was, SFX installed a bunch of air pumps at the bottom of the canal to create the rebound of the water against rocks that weren’t actually there. Then we added the rocks to create a couple of near misses and make the path quite dangerous.

5. The final trench run

There were quite a few very large real explosions used here. Not only do you have the explosions and the main actor, there were also many extras, and the camera! [Rocheron noted at the VFX Bake-Off that for the final trench run, the actor was hit twice but got up and kept going. It was important to get the take because it involved a whole lot of practical explosions, so the crew carried on shooting].

For the camera to run back fast enough, it had to be on Jeeps to pull back at the required speed as Schofield goes into a full run. There were a few transitions within that shot to connect two different sets and do a blend between different takes for the best performance.

We did things like create the ground to hide the charges for the explosions, but a lot of it is practical FX. We also went back the next day in the same location and shot a bunch of elements that we used to comp into the final shots, that were much closer to Schofield, or a couple in the distance.

My favorite moment is an explosion that actually goes off behind the camera, so the camera could track back into the original smoke of it. It really gave you a sense that things were happening not only in front of the camera – it was actually the whole battlefield.