Production VFX supervisor Guillaume Rocheron discusses the special challenges involved in creating the illusion of grim reality in Sam Mendes’ Oscar-nominated epic World War I drama.
Guillaume Rocheron is no stranger to the world of digital artistry. In a 20-year career, half of it working as a visual effects supervisor, he has helped created indelible images in such films as Ad Astra, Godzilla, The Secret Life of Walter Mitty, and Life of Pi. For his work on Pi, he was nominated for nine best visual effects awards, winning seven, including a VES Award, a BAFTA Award, and an Oscar. Yet, despite his long experience and industry recognition of his mastery, nothing quite prepared him for the challenges he faced in his work on Sam Mendes’ 1917 (for which he again won a BAFTA Award, accepting on behalf of his MPC Film crew of over 600 artists, and is nominated for an Academy Award).
We recently spoke with Rocheron about the unprecedented demands made on him by Mendes’ “single shot” tour de force, and the ingenious solutions he and his colleagues devised to realize the director’s vision
AWN: I want to start off by saying, as someone who spent a lot of time studying World War I history in high school and into my early college years, how much I appreciated 1917. It was a tremendous film and, even though special effects played such a large role, it really felt like a true “film,” shot with film, if you know what I mean.
Guillaume Rocheron: Well, thank you so much. Much appreciated.
AWN: So, to start, could you briefly tell me about the scope of your duties on the film?
Rocheron: I was the production-side visual effects supervisor. So, my role was to work with Sam Mendes, [editor] Lee Smith and [cinematographer] Roger Deakins to make sure that the visual effects work was absolutely invisible because, as you mentioned, there are some movies where the task of visual effects is to create spectacle or create something that doesn't exist, and 1917 was a much different use of visual effects. It's not a movie about spectacle, it's a movie about the journey of two young soldiers and the horror of war, and the last thing you want is to distract from the story.
When you make a movie that is all in one shot, obviously the main task of visual effects is to stitch the whole movie together and make it look completely continuous. It's funny, people ask me how many shots we did and I'm just like, “Well, I can't really give you a shot count because it's not a traditional movie.” Some of the sections that we stitched together were maybe five-to-seven minutes long, and some of them were a couple of seconds. But one thing I can say is, in the end we touched 91% of the footage. Whether it was for stitching, whether it was for environmental work or effects simulation, or just simple paint work to remove modern architecture. The work covered the whole scope.
Roger’s visual design was meant to ensure that the camera is never a character. You want to be with the guys and it's all about being immersed in the experience. It's a rule that we really had to keep in mind because, in the past, in stitching things together we would kind of force shots to connect. It's like, okay, let's use a piece of architecture so you can blend the tapes together. And this movie was a journey that mostly took place outside. You're in an ever-changing environment and you have to just make it look like a long continuous journey. So, we used a wide array of different techniques to connect the shots together, making sure that it would be completely imperceptible to the audience, not only technically, but also artistically, where the camera can never feel forced. You have to really be mindful of not making CG moves that start to look forced, or that betray the naturalistic approach of the whole thing.
And to make it even harder, we made the movie all in 4K IMAX with a camera that Roger developed with ARRI – the ALEXA Mini Large Format, which combines the lightweight ALEXA Mini body with a large-format sensor. So, the camera could be carried around and be very fluid, but with incredibly high image resolution. We just had to figure out what would produce the best result, including in transitions to full digital shots. Sometimes we used little pieces of the sets so we could transition from one take to another in a very simple way. And sometimes we had to do some very complex warping and morphing – we did it on close-ups and in places you would not expect. Because again, it was all about, hey, we can't force the camera to go somewhere just for the sake of being able to do the transition, so we have to be smarter than this. And luckily technology today allows you an incredible level of sophistication in terms of manipulating images in 2D and also creating photorealistic CG.
But, in a way, we really had to relearn our tricks. Because normally the basic units in visual effects are the shots. They’re your currency. It's how you quantify work, it's how you break it down, and also how you design your whole workflow. But that’s also how you learn all your tricks – you only have to suspend disbelief for a few seconds and then there's a cut. You learn how to work with cuts and how to fool the audience into thinking they're looking at something real through cuts.
In this movie, in the extended scene in which the soldiers cross no man's land, for example, the sequence is seven-and-a-half minutes where you’re looking at the same environment. So, you can really study it. You're slowly moving with the two soldiers and it's absolutely unforgiving because it's open environment, daylight, 4K IMAX, and it's seven-and-a-half minutes of CG on the screen without ever cutting away from it. And so you have to think about it differently because it's not just that you have to look real from shot to shot. You have to look real when someone’s staring at it for seven minutes. And the moment the audience feels that they've been tricked, it breaks the illusion. So it was a tremendous amount of pressure because it's like trying to do a magic trick that lasts for two hours instead of four seconds.
AWN: A lot has been written about all the preparation that went into the film. What did you have to begin with? Did you have previs? Did you have storyboards? How did you set this up so that when you started production the film could be shot the way it needed to be shot and you could get what you needed to get for the VFX production to follow?
Rocheron: When you make a one-shot movie, everything has to line up. Your set has to be exactly the right size so that when you have a walk and talk – which is a lot of the movie – where they're moving through the scenes and space, you have to make sure that whatever location you pick or whatever set you're building will exactly match the duration of the scene. Sam, Roger and the actors would walk the scene, in back lots or other empty spaces, and figure out, "Okay, we need the set to be 332 feet." And then you build your set.
As far as visual effects, the prep was like any other movie – it was really important to make sure that everything was lining up and that Roger had a path for his camera.
Sometimes the camera had to be on a crane, sometimes it had to be on a vehicle, sometimes it had to be handheld using a Trinity or Steadicam – whatever was the most appropriate tool to film each section of the film. And sometimes the camera department did some amazing practical transition where they would lift the camera from the Trinity rig and hook it to a wire and then maybe pick it up on the other side. And when that was impossible, that's where we'd come in and create a transition.
There is one in no man's land, for example, when Schofield and Blake are in the sap trench. And Roger wanted to shoot a slow push-in behind them through the trench using the Technocrane to get a really smooth move. But the problem was that as soon as they get out of the trench and into the open, the terrain is too rough. You can't push a crane through it and you have to carry the camera on a handheld rig. So, that's where we had to do a transition – a blend to a take – that was going to be in plain sight. It wasn’t like, in order to do the blend, we could have the camera look away, or look at the sky, or wipe behind the tree. We just accepted the challenge, saying, okay, we can do this transition with 2D, 2.5D, full CG, a mix of things.
AWN: Whatever's needed.
Rocheron: Yeah, there's no one solution fits all. And I think that's where the stitching was interesting.
AWN: Tell me about the dynamic of working with Roger and Sam. How did you ensure that you got what you needed for VFX production without getting in the way of the cinematography?
Rocheron: I think that comes down to the prep. Both Sam and Roger are very precise people. Once you agree on a methodology, everybody's on board. And everybody understands that it's a huge collaboration to do a film like this. You have to cut the movie as you shoot it to be sure that the pace is working, to look at it in context. You have to do some quick stitching just to know that something’s going to work or not. We had a compositor on set doing some rough proof of concepts, plus editorial was doing theirs.
It was also really interesting in post, where Roger was with us for part of the time. For me and for Sam, it was really important that, whenever we were doing CG camera work or CG lighting, I would always discuss it with Roger. And he would look at it from the perspective of the cinematographer because, again, it was not a movie where you have cinematography and you have visual effects. Ultimately you just don't want to see the difference. So, it was very collaborative. The same with editorial. It wasn’t like in a traditional movie, where you swap takes around and you know how to approach things. It was really looking at the movie as a group and discussing what we could do to help the story, or to go quicker from this place to this place, or to improve an element.
And then, when it came to doing all the 4K high-res work, we had to actually review it in the DI. There was no way we could use a 4K workstation because you needed the whole film to be there. And also, you needed to be able to color it. Coloring a one-shot movie is very complicated. So, Roger, Sam, Lee and I would just look at each section because we didn’t have the breakdown of shots to help us draw a line anywhere. It was a very collaborative environment to review the work and make sure that it worked in context.
AWN: With these big films, there are always immense challenges, even when they’re not conceived as a single shot. There are a lot of moving parts from the first day you're on it until the day you leave it. What were the biggest challenges in your area of the film?
Rocheron: The one-shot factor definitely makes everything you do infinitely more complicated because you have to change the way you work. Even to break things down for artists is a challenge. We did a sequence in the river, for example, where Schofield goes down the rapids and then goes over a waterfall. We shot it in a waterpark, like a canoe training center, which gave us the basic water. And we worked with special effects to get a lot of practical splashes and water around the main actor. But then we had to extend the water and we had to create the whole environment around it. It's like you're looking at a frame that is mostly digital.
And water shots are complicated, but water shots that last for three or four minutes become very complicated because you need a piece of simulation for one section and then you need a piece of simulation for another part of the scene. Where we're going to do a stitch, I need a digital splash to help me do the stitch or I need a patch of digital water. So, it's really rethinking the way you design and execute the work because it's really a completely different beast. You can't approach it the same way you would any other movie. And there's no formula for it. There's no easy way to do it.
And the other challenge, as I mentioned before, is to be absolutely invisible as much as possible. And we used a lot of really fantastic practical effects. Our special effects supervisor did some really brilliant explosions and then created those magnesium flares to illuminate the burning city at night, which was an amazing collaboration between Roger and special effects, because the special effects became the sole light source for the scene. And it required a lot of engineering, a lot of planning to really get it right.
You can't have a moment where the audience is like, "Oh yeah, that's a visual effect."
And I think these two aspects were certainly the most challenging, because you can really study all the frames and, in 4K IMAX, it's a lot of pixels.