Gravity's visual effects house Framestore writes an account of their elaborate process that led to the spectacular and groundbreaking film.
They write, "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."
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