Oscar-nominated Neil Corbould on supervising Gravity's special effects

Clooney and Bullock's real bodies were not shown in space, Corbould reveals

Sandra Bullock and George Clooney in Alfonso Cuaron's Gravity (AP)

Gravity special effects supervisor Neil Corbould, has been nominated for an Academy Award and a Bafta in the Best Visual Effects category this year – along with Tim Webber, Chris Lawrence and David Shirk.

His input was crucial in translating Gravity director Alfonso Cuaron’s sometimes impossible vision onto the big screen. “We have been asked many times: did we go into space to film any of the scenes?” says Corbould, who has just finished working on Ridley Scott’s Exodus, which stars Christian Bale as Moses.

“We wanted people to feel like they were in space or watching NASA footage. I think we achieved that.”

In pre-production meetings with Cuaron it became apparent that the way forward was to use computer-generated effects most of the time.

“But to start with, Alfonso wanted us to build a massive set that could spin and rotate so that the action could be filmed physically. But that would have cost a fortune – and also the results would not have been so good. The most magical aspect of Gravity is the mixing of computer-generated effects seamlessly with some real effects,” says Corbould.

When Sandra Bullock and George Clooney were filming Gravity, they were placed in specially constructed mechanical rigs, made by Corbould, to turn and twist their bodies in different angles before the computer-generated imagery was added. “It was a combination of the camera move and the rig move that achieved the floating effect,” says Corbould. “Ninety per cent of the time they were in a harness – or sometimes they sat strapped to a bicycle seat that was attached to a turn-table. They spent four or five demanding hours at a time in these rigs.”

When Bullock and Clooney are shown out in space, the only real part of them is their faces, says Corbould – the rest is computer-generated. But when Bullock is in the main spaceship, she wore a carbon-fibre harness attached to 12 wires, so the production team could float her around and show off her body when she took off her spacesuit. “She was put in a rig that was a basic replica of the spaceship. The interior was made of cardboard and polystyrene, just to give the actors a bit of geography.”

Corbould started his career as a special-effects runner on Superman in 1978. “In those days we used lots of miniatures to create large scale destruction; these days, it’s more computer-generated.”

He won his first Oscar in 2001 for Ridley Scott’s Gladiator and three Bafta awards for The Fifth Element, Saving Private Ryan and The Day After Tomorrow.

“When I eventually saw the whole of Gravity, it blew me away,” says Corbould. “Before then, I only saw it in its raw form, with actors spinning around in a rig.”

‘Gravity’ is out on Blu-ray 3D and Blu-ray on 3 March