Heading Into Space
Gerard Butler is propelled into space to work on his satellites in a zero-G environment. Audiences have seen zero-G approached before in a number of different ways, which encouraged the Framestore team to try new techniques to make the work stand out. Full digital doubles of actors Gerard Butler and Alexandra Maria Lara were created, with pioneering photogrammetry facial capture methodology employed for shots which couldn't have been achieved even in a truly weightless environment.
“We decided on a methodology we’ve not attempted before, which we initially called the 4D process, but later re-christened the Doppelganger technique,” explains Rob Duncan, VFX supervisor. “We shot the actors in a multi-camera array rig, but rather than using stills cameras we employed 16 Red cameras to capture their full performance, including the delivery of dialogue.”
These cameras were precisely timecode-synced so that the Framestore team could use photoscan software to stitch the moving footage together to generate 3D faces which animated over time, hence the name 4D.
“During the lengthy R&D phase, we realized that we would be able to completely relight the facial performances after they were captured, achieving an extra layer of realism and integration with the ever-changing space environments - something that we didn’t think would be possible when we started.”
Framestore is no stranger to building the ISS in CG, having done so in Gravity (winning the Oscar for Best VFX). This version was larger and very different in design to the real thing: around 1.5 kilometres long, compared to just over 100 meters. It was built in kit form, using a library of objects such as doors, panels, solar arrays, pipes and antennae, which were then repeated many hundreds of times each, in different configurations.
This instancing technique kept the overall polygon count at a level that the digital model could then be rendered into shots in a reasonable amount of time.
“The ISS is gigantic in this film - and then we had to destroy it,” says Alexis Wajsbrot, CG supervisor. “It was about 20 times bigger than the one we built for Gravity, so although we were positive about the challenge, we needed to develop an Instancing tool, fInstancer, to manage the build.”
The Testudo Net is a vast array of malfunctioning climate-controlling satellites linked by solar panels: an incredibly ambitious build, with each hub performing a different task in governing the world's weather. The team received concepts for the look of the hubs and started modeling variations of them, focusing on a few shown in close-up shots later in the picture. Having been on set at the NASA compound in New Orleans, VFX supervisor Christian Kaestner worked with the same instancing methodology (used for the ISS) to tackle their build.
“In order to achieve a complex and highly detailed model and make it renderable for wide and close-up shots, we used a lot of instancing,” explains Kaestner. “We used a Lego-block approach for the whole net, and even the hubs. We then went on to use this tool for King Arthur: Legend of the Sword and Alien: Covenant, but our work on Geostorm pioneered this technique.”
The team was also challenged with building several interiors inside the ISS, as well as taking care of its destruction as it bursts into flames. The scale of the work performed was the biggest challenge, but one that the team found exciting: “We had a great relationship with our client, and the work was fun and collaborative,” says Kaestner. “Dean Devlin was in all of our meetings,” adds Wajsbrot. “He was very involved with the process, which made it a really rewarding experience.”