The Aeronauts – VFX Q&A

by Graham Edwards

The Aeronauts - VFX Q&A by Cinefex

Set in 1862 and based on true events, The Aeronauts follows daredevil balloon pilot Amelia Wren (Felicity Jones) and pioneering meteorologist James Glaisher (Eddie Redmayne) on a record-breaking ascent into the upper atmosphere. Their journey — in a giant gas balloon called Mammoth — reveals not only the hidden wonders of the natural world, but also its perils, and all too soon their voyage of discovery becomes a fight for survival.

Tom Harper directed the period drama, with Louis Morin in the role of overall visual effects supervisor. Framestore created the majority of the film’s cinematic illusions, with Christian Kaestner as visual effects supervisor and Stuart Penn supervising preparatory work for the main shoot. Rodeo FX delivered a rousing finale, led by visual effects supervisor Ara Khanikian, and Alchemy 24 provided additional effects support. The Third Floor visualization supervisor Jason Wen oversaw previs and techvis for the film.

Louis Morin

CINEFEX — The production hired aeronautical engineer Per Lindstrand to build a full-scale gas balloon for the production shoot. How much of that balloon footage made it into the finished film?

LOUIS MORIN — The real balloon was great reference, but there is only one live shot of it in the movie, and one shot of the actors in the basket in a live flight. The rest is visual effects. Roughly 70 percent of the movie was shot in front of bluescreen.

CINEFEX — Bluescreen shoots can be sometimes be difficult for actors. Did you have any way of previewing the background environments on set?

LOUIS MORIN — Well, my first idea was to shoot plates and create 360-degree environments that we would actually use on set. That was ultimately considered too time-consuming, so instead Framestore developed a custom augmented reality iPad application called fARsight. We had our sky backgrounds prepared, and every time we were ready to shoot, Tom Harper and George Steel, the director of photography, were able to see where we were. And so were the actors, of course. It was a great tool to make sure the lighting matched the background environment, which is the key in bluescreen shooting.

Eddie Redmayne stars as pioneering meteorologist James Glaisher in "The Aeronauts."
Eddie Redmayne stars as pioneering meteorologist James Glaisher in “The Aeronauts.”

CINEFEX — These backgrounds were 360-degree wraparound skies?

LOUIS MORIN — Yeah. I shot with a multi-camera array in Louisiana for five days with six 8K RED Helium cameras — the first time this had been done. All those plates were stitched together and heavily matte-painted, and those became our environments.

CINEFEX — Did these same environments make their way into the final shots?

LOUIS MORIN — No. They were good enough to help on set, but there was no way we could finish them to a high enough level. Everything was redone in post. I shot more plates with the multi-array, this time in South Africa. At one point we went up so high that we needed special oxygen tanks for the helicopter. We had all six 8K cameras running every second. You lose a bit when you stitch them together but we still ended up with final plates at something like 42K. Imagine the data — it was insane! We used those plates either as a full live-action environment, or we used just part of them. Then everything was enhanced by mid-ground CG clouds.

CINEFEX — For the storm sequence, Framestore went the whole hog with fully volumetric digital clouds.

LOUIS MORIN — Actually, there are two big volumetric cloud sequences. I have to say, trying to do clouds in CG is a nightmare. From the way sunlight goes through and scatters in infinite ways, to the infinite levels of gradation from light to dark — the guys went nuts creating the amount of detail we needed.

CINEFEX — There’s a nail-biting sequence where Amelia climbs up the outside of the balloon. What challenges did that bring?

LOUIS MORIN — The actors did a good chunk of their own stunts. Felicity Jones was so good. I couldn’t believe a main actress would be as daring as her. She had bruises all over the place by the end! The same for Eddie Redmayne. At some point they had to stop the shoot because he had a sprained ankle. They even did some stunt work on the real balloon — a stunt woman climbed up on top while it was actually flying. Out of respect, we kept her stunt work in our shots, although the balloon and the environment are totally digital.

CINEFEX — The drama continues into the descent sequence.

LOUIS MORIN — Which is funny, because that descent would be so boring to look at in reality — you would probably be falling through just one layer of cloud. Our idea was to have multiple layers everywhere, so we would never stop going in and out of cloud, just to enhance the drama. It’s almost like a Road Runner cartoon when Wile E. Coyote falls down and the clouds go up past him!

CINEFEX — The camerawork throughout is quite naturalistic. Was that a conscious creative decision?

LOUIS MORIN — Absolutely. George Steel handheld the camera for almost all the movie, and if we had a camera in the air it had to feel like a helicopter shot. There’s a shot where Amelia slides down the balloon, and the camera follows and does a 360-degree flip. Tom wanted that to look like it was being filmed by a guy with a parachute who just fell. That’s great for me, because I hate when camera moves are too perfect and feel CG. We were really careful to make sure every shot had that handheld movement. Sometimes it’s those imperfect details that make it real.

CINEFEX — All this helps The Aeronauts feel realistic, but the film also has a magical quality. Was there a balance you were trying to strike there?

LOUIS MORIN — Tom Harper wanted it to look real, but like those moments of reality that you see maybe once in a lifetime. For my part, I always try to achieve seamless visual effects, but on this film we were taking it beyond that. We were bending reality to tell a story. An old lady came up to me after a screening in Los Angeles, and said. “I had to close my eyes because I got vertigo.” That’s exactly what we wanted to achieve. We wanted to go beyond just making things look real. We wanted to create sensation.

Felicity Jones stars as daredevil balloon pilot Amelia Wren in "The Aeronauts."
Felicity Jones stars as daredevil balloon pilot Amelia Wren in “The Aeronauts.”

The Third Floor

CINEFEX — What were the major previs sequences you handled at The Third Floor?

JASON WEN — We worked on the opening at Vauxhall Pleasure Gardens, various balloon establisher shots, the storm sequence, the butterfly sequence, the balloon at its maximum altitude and the crash. The director shared with us a completed script and extensive boards. We tried to stay close to the spirit of the boards, concentrating on camera, lighting and blocking balloon animation. The biggest challenge was keeping the movement of the balloon and camera relatively realistic, and based on what could be achieved with the accurate curvature of the earth. To achieve this, we modeled the Earth to scale and built different versions of the sky and Earth to represent the different altitudes outlined in the script.

CINEFEX — Tell us how your techvis helped with the live-action shoot.

JASON WEN — Several shots were engineered to a specific stage in West London. We constructed techvis using the plans for the stage, also incorporating a 64-foot techvis crane rig matching what the client planned to use on set. We also did techvis for a number of helicopter shots, to inform the shooting parameters that would be required from the air.


CINEFEX — Tell us about the early days of the project.

STUART PENN — I remember we had our first production meeting at Ealing Studios in February 2018. It was a roundtable meeting with Tom Harper, the producers and the heads of departments. Tom is a very collaborative director, and we worked our way through the script discussing methodologies and how the different departments could work together to achieve his vision. The team also included world renowned balloonist Colin Prescot, who provided the team with valuable real life knowledge and experience of an aeronaut.

CHRISTIAN KAESTNER — Our brief was clear from the beginning. The visual effects work needed to support storytelling and remain invisible otherwise. In order to allow the audience to fully immerse themselves into the story, our integration had to be seamless. At no point could we afford to take the viewer out of the film.

CINEFEX — Did you get a chance to go up in a balloon yourselves?

STUART PENN — Yes, Tom was keen that heads of departments and key members of the crew got the opportunity to experience balloon flights. Felicity Jones and Eddie Redmayne did several flights to gain the experience of real aeronauts. I was lucky enough to have two flights in a hot air balloon. They were inspirational. They definitely helped to bring authenticity to the project, and to relate to experiences of the characters in the film.

CINEFEX — We’ve heard how you worked with The Third Floor during the previs phase. It seems like preplanning was the key to this project.

STUART PENN — Oh, the film was meticulously planned. I supervised the previs of key action and balloon establisher shots, and also worked closely with the stunt and special effects teams. We would check the action was achievable and identify any shots that would need digital actors — although, for the most part, we tried to use footage of the actors. Working from the previs, the stunt team would rehearse shots and film stuntvis that could be fed back to the previs team to make adjustments.

CINEFEX — You handled the entire flight of the Mammoth up to the final part of the descent. Can you summarize the scope of Framestore’s work?

CHRISTIAN KAESTNER — We start with the opening sequence at Vauxhall from where the Mammoth was launched. We extended the partial build of the stadium and filled in a crowd of thousands. Right after take-off, Amelia and James glide over a full CG build of 1862 London. The balloon disappears into thick clouds and ends up in an unexpected storm inside a cumulus cloud. After the storm, we break through the clouds to see the mesmerizing beauty of an endless sea of clouds wonderfully lit by a late afternoon sun. As we continue the ride we encounter a swarm of several thousand butterflies elegantly dancing in the wind, before we reach the moment of breaking the height record.

CINEFEX — At which point the lack of oxygen starts affecting our heroes.

CHRISTIAN KAESTNER — That’s right. James passes out, and Amelia attempts to climb the balloon and break open the top valve, which has frozen shut. We used carefully art-directed sun positions and camerawork to enhance the effect of vertigo, combined with stunning visuals of cloudscapes and stars. After the valve is opened, Amelia also passes out and the balloon begins descending with her lying on top, creating an almost graphical top-down image. The last of Framestore’s sequences shows Amelia’s struggle to re-enter the balloon and wake James in lower altitudes. A beautiful and intimate moment occurs when it starts snowing and the descending balloon catches up with falling snowflakes which appear to float suspended in mid-air.

CINEFEX — What was the most challenging aspect of the show for you?

CHRISTIAN KAESTNER — Without a doubt, translating the striking concept art from Framestore’s art department into believable, photorealistic volumetric renders. Tom had a very clear vision of what the establishing shots needed to look like. That was fantastic because it gave us a wonderful guide, but at the same time there was little room for shortcuts, technically or visually. Even with today’s render power and physically accurate shaders, mimicking the light scatter within the vast volumes of our cloudscapes was a difficult exercise and required all hands on deck from the whole team, from shader writing to compositing.

CINEFEX — The aeronauts travel through many different atmospheric zones, each of which has its own character. Was it hard to keep track of continuity?

STUART PENN — Well, a key part of the story is the timeline of the balloon ascent. We had diagrams and charts that plotted the height of the balloon through the film, and we linked this to the temperatures they would experience and the types of clouds they would see. Working with Tom, I created per-scene mood boards of clouds, lighting and atmospherics. These were then used to create templates for the backgrounds for each scene.

CHRISTIAN KAESTNER — Yes, and Tom had a very clear idea of what he wanted his sky cinematography to look like. The shape of the clouds, the screen composition, even the color palette, were all well-established. Tom worked closely with Martin Macrae in our art department to bring his vision to life. It was a pleasure turning Tom’s vision into these remarkable images.

Rodeo FX

CINEFEX — Rodeo FX handled the climactic balloon descent. What was your reaction when you found you’d be handling this wild ride down through the sky?

ARA KHANIKIAN — You know, there’s something very exciting, and somewhat terrifying, when someone tells you, “We need to design a scene where a 19th century deflating balloon freefalls through layers and layers of clouds and crash-lands in trees in a period-accurate English countryside during a glorious sunset!”

CINEFEX — The Framestore team identified the cloudscapes as being one of the most challenging aspects of their visual effects work. Was the same true for Rodeo?

ARA KHANIKIAN — Yes, our main challenge on The Aeronauts was creating and lighting photorealistic cloudscapes in CG. It was clear to us that we could not use a digital matte painting approach, based on how dynamic the shots were in terms of lighting, camera, and overall complexity of action. Using Terragen, we created a number of custom cloudscapes with diameters ranging from three to six miles and scattered them into two separate cloud covers, at different altitudes. We used anisotropic volumetric effects for distant build-up of atmosphere, natural light spill, warm glow from sunset, and low-lying humidity on the Earth’s surface.

CINEFEX — There must be some interesting physics going on inside a deflating gas balloon. How did you simulate all that rippling silk?

ARA KHANIKIAN — One of the big challenges was developing the look and the interaction of the fabric with its enveloping rope netting. The simulation of the Mammoth was done accurately by having a CG volume exerting pressure at top of the balloon, simulating how hydrogen gas would react for additional realism. Created the proper hierarchies and constraints allowed us to deflate the balloon, while keeping control of the tension of ropes and their connection with the hoop from the bluescreen photography. We created a master scene and choreographed the Mammoth’s path and speed from start to end. This removed any subjectivity in regard to height, horizon line and speed from shot to shot. Designing the entire choreography in one master layout scene ended up being a very smart decision on the show — nobody ever second-guessed layouts in shots.

Special thanks to Rachel Aberly, Christina Baron, Agathe Jarnoux, Carmen King and Kara Misenheimer. Images copyright © 2019 by Amazon Studios.