When starting the project, no one guessed how much CGI would be needed to produce the final film.  “There was a stage initially where it was going to be made with actors in real space suits,” shared Tim Webber, VFX Supervisor on the project, “they would have been hung up on wires on partial sets and we would have extended it and put in the background.” In the end considerably more of it is CGI than first discussed, and in fact considerably more of it is computer generated than real. In the majority of shots the only elements captured with a camera are the faces. The vastness of space, the Earth, the stars (all 30 million of them), the space shuttles, Hubble Telescope, the International Space Station (ISS), the copious and equally villainous fragments of debris, even the space suits: they were all made by visual effects artists at Framestore.

A sizable problem to solve was the simulation of zero-gravity. Collaborating with Bot & Dolly Motion Control and the on-set special effects team, cameras were strapped to huge robotic arms and actors George Clooney and Sandra Bullock were put in a variety of different rigs, many newly developed for the film.  Then the solution of the lightbox was hit upon and the cramped LED box known on set as ‘Sandy’s cage’ took over a large part of the filming responsibility.  A 20-by-10-ft. (6 by 3 m) structure, it was covered with 196 panels of 4,096 LED bulbs each to simulate the extreme light in outer space. The camera moved around Bullock, achieving the illusion that it is her that moves. It could zoom in and out from any position and it would race towards her and stop dead, just centimetres from her face. This highly unusual and groundbreaking VFX-led filming process led to the lightbox being named as one of the year’s best inventions by Time Magazine.

Viewed from every angle, inside and out, and then stunningly destroyed, the International Space Station (ISS) was the biggest of Gravity’s thousands of asset builds – ending up as a 100 million polygon model.  A big design challenge, the ISS, Hubble Telescope and the Atlantis and Explorer space shuttles are so iconic that many people will recognise them, so creating them in a photo-real way was a big undertaking. The team had to source reference photographs really carefully and question all design choices made. It’s a lot more complex way of building things than simply adding details just so the render looks prettier – this had to be functional and believable.

As well as the sets, Framestore were also tasked with the creation of the costumes, specifically Sandra and George’s space suits. 'The goal, which sounded simple enough, was to make the astronauts look real', says Head of Rigging Nico Scapel. 'The complexity there is that they had to look right, from far away to extreme close-up, and they had to move right – every fold on their suits – across very longs shots and changing lighting conditions'. They were unthinkably detailed and each suit could have a few million polygons, between ten and a hundred times the resolution the team might normally have worked at. CFX artists used a program that was designed for the fashion industry to digitally sew the suits together. For the NASA suit, the starting point was a selection of photos and video references. The team had to get the right amount of fabric to ensure that it fits the character properly, turning them into digital tailors of a sort.