The Aeronauts
TREVOR HOGG LEARNS HOW PRODUCTION DESIGNER CHRISTIAN HUBAND AND FRAMESTORE WERE ABLE TO MAKE VISUAL EFFECTS THAT SOAR TO GREAT HEIGHTS IN THE AERONAUTS…
Go behind the scenes of the impressive visual effects in adventure film The Aeronauts
Inspired by meteorologist and astronomer James Glaisher and aeronaut Henry Coxwell breaking the world flight altitude record in 1862 by soaring to 36,000 feet in a coal gas filled balloon, screenwriter Jack Thorne (His Dark Materials) collaborated with filmmaker Tom Harper (Wild Rose) and Amazon Studios to make The Aeronauts, starring Eddie Redmayne and Felicity Jones. With over 80 per cent of the action taking place above England under various weather conditions, visual effects had a pivotal role to play in making the biographical adventure film a cinematic reality. Overseeing the CG contributions of Framestore, Rodeo FX and Alchemy 24 was production visual effects supervisor Louis Morin (Arrival), while the physical builds were the responsibility of co-production designers Christian Huband (Justice League) and David Hindle (Bohemian Rhapsody).
“The one image that sticks in my mind when it comes to the sky
was a print that was used in the book about the balloon journey that was done by Glaisher, and it was a stylised print that had The Mammoth above the clouds along with shooting stars,” recalls Huband. “This was a provocative, beautiful thing, slightly fanciful because I don’t think at 37,000 feet you can generally see the stars unless it’s at the end of the day or night. The decision to show the stars was something that has a certain theatricality which feeds into the story and performances. We did a sky chart, which was a graphic representation of what altitude they’re at and the time from the butterfly scene to the snow and ice scene. In the end, you send a helicopter up, which they did over South Africa, Louisiana and in different parts of the world, to film plates and you have to work with what you get.”
“Originally when we took on the project it was supposed to be bluescreen live-action, sixcamera array backgrounds, and 2D compositing work,” reveals Framestore VFX supervisor Christian Kaestner (Captain Marvel). “Obviously, as you do the movie, the director will say, ‘I want it to actually look like this.’ Then all of a sudden, you’re in art-directed skies and clouds. Since we were using our own renderer, Freak, we were able to implement the latest render technologies and algorithms and optimise them where we could. The render algorithms are written in a way where they react specifically well to all possible lighting scenarios. But above the clouds we were exposed to bright sunlight, so we could cut corners in our shader algorithms.
“On top of that scenes were being intercut between six RED Monstro camera array stitches and CG shots. We ended up rendering high-resolution cube maps which we were able to tile to our desire. The big cloudscapes above the clouds were over 100 rendered tiles, so if a 50mm lens was needed we would not be above the resolution. Volumetrics were then dressed in-between the camera and basket, and between the basket and the distance for parallax and sense of travel.”
“Tom worked closely with the art department to make meticulous concept art of establishing shots” CHRISTIAN KAESTNER, VFX SUPERVISOR
Plates were shot in New Orleans by Morin to get some different altitudes, and Framestore provided an ipad app called Farsight that enabled the 360-degree stitch to be viewed and helped to determine such things as the placement of the sun. “Luckily, we also had South Africa plates that Tom selected which gave us an idea of his sense of what the cloudscape should be,” remarks Kaestner. “Tom had a good vision of what he wanted for the storytelling and worked closely with Martin Macrae in the art department to make meticulous concept art of establishing shots and of what the cloudscapes should feel like, including the colour palette, the amount of scattering and the desired lighting. It gave us a good guide and we could focus on the technical side of things.” The concept art of the cloudscapes was indispensable. “It’s such a subjective thing so it was tricky to get the right look that was suitable for each need,” notes Framestore CG supervisor Benjamin Magana. “Our camera layout had to have a rough way of looking at the environment.” There was custom modelling to the concept art and procedural generation of basic shapes with additional surface detail for the cloudscapes, explains Kaestner. “One scene was 60km wide and had 550 instances of different clouds.”
A big story point was for the audience to be able to distinguish between the different altitudes. “Because we had basic detailed information for every stage of the balloon ride, such as how fast it would ascend and how high it should be, the layout department took on an important role because the environment department would then accurately put the
sun positions and haze,” remarks Kaestner. “For example, there is less haze at 30,000 feet so you will have a different visual result.” Wispy clouds and rain can exist at the lower altitudes whereas high up is extremely dry. “Sometimes in Montreal when it’s extremely cold and the sun is out you get ice particles floating about. I suggested this to Tom and he was like, ‘Okay.’ As the show progressed, we were able to dress them in as needed. Towards the end of postproduction, Tom kept on saying, ‘Christian, those ice particles are gold!’ It was helping to tell the story so much and added a little bit of life to the photography.”
A major action sequence has Amelia Wren (Felicity Jones) climbing the frozen balloon in an effort to reignite the extinguish flame. “One of the biggest challenges was the curvature of the set piece didn’t quite match our CG build,” reveals Kaestner. “For some of the shots we roto Felicity Jones out of the plate and manually realigned all of the knots, nets and ropes because some of it needed to be extended down anyway as the set wasn’t high enough.” The only practical element shot in a cold environment were the breaths. “After the shoot was done and we had the cut, Louis and our compositing supervisor Anthony Luigi Santoro planned out the lines and breathing that we needed. Breath elements were
shot in ‘the fridge’ against black. We took accurate measurements of everything in order to put the breath elements back in at the proper scale. In Nuke, we used the head tracking system for each shot that needed the breath element and put those elements onto cards. The head movement did not always correspond with the breath element, so we needed to be clever when releasing the card into space before the head was turning. There were over 250 breath elements that were heavily art directed per shot just to get the right sense.”
A swarm of butterflies makes a dramatic appearance. “It was something that we kept working on because we wanted to change the look of the butterflies,” states Magana. “We had to extrapolate from the hero butterfly to the swarm, which was a particle simulation that had cycles of butterflies flapping their wings. It was a huge swarm. We had to devise how to get the right motion blur for the particles and make the animation cycle for the flapping of the wings as accurate as possible.” There were some practical butterflies on set that were all replaced by CG versions. “The one on the finger of James Glaisher was a rotomation of the actual one,” explains Kaestner. “We have done butterflies before but more like a hero creature. In this show, there were 7,249 butterflies that needed to look the same even if we couldn’t afford to render them all with the same groom. We visually decided what was necessary for each
“We had to make the animation cycle for the flapping of the wings as accurate as possible” BENJAMIN MAGANA, CG SUPERVISOR
group of butterflies. The hero ones had high-detailed scattering with a groom on their wings so it would feel like velvet, but the light needed to be coming through so you can see these little strands.”
The liftoff of the Mammoth was an entirely different challenge compared to aerial scenes. “Vauxhall Gardens itself was our biggest set build with the arena, platform, stands, fairgrounds and stalls,” notes Huband. “Our art department team did a 3D model of the stands so it could then be sent on to Louis to build in whatever medium was needed to work in visual effects. For a while we weren’t sure how much we were going to be permitted to build and whether it was going to be the lower story. In reality it became two stories. The only constraint in fact was the number of extras and costumes that we could afford to populate these stands. There was no point in building an empty stand.” The sequence was more straightforward for Framestore who are used to building cities for other projects. “We had this epic 2,000-frame shot as Amelia and James slowly fly in a helicopter plate, then we took over and it became a full CG shot. We built a library of buildings that included residential and factories as well as smoke stacks and boats. We dressed in crowds with horses and carriages. Because it needed to feel like London of 1862, historical maps were projected on the floor and we laid out our buildings. London is distinct in its house layout and roads are recognisably crooked to each other. We used historical data and did instancing of various versions of numerous models.”
“Building the real balloon and having the privilege of somehow getting Eddie and Felicity up in that was the biggest challenge,” notes Huband. “They flew and even crashed. The insurers would be freaking out if they had known! To be able to do that is a career high. Seeing Helen Bailey, the stunt double for Felicity, climb the balloon at 2,000 feet up in the air and then get to the top and ask, ‘Do you want me to do it again?’ She was mad and amazing! I can’t wait for people to see Amelia climb to the top of the balloon. I’m hoping that it feels like Free Solo or that sort of precipitous, or even worse in a way because it’s so wobbly and bouncy – that’s not something you’ve seen in any films. For me, the inherent challenges in that were difficult and rewarding in equal measure.”