Titanic director James Cameron has a button that makes him 18ft tall. He simply shouts across to a technician, and he’s suddenly towering over the actors, shooting down at them from an angle that would have previously been impossible without a crane or helicopter.
Another button press, and he's a mere 12ft; press again, and he's tiny, dwarfed by the actors around him.
The actors aren’t really there, of course. Cameron is holding a ‘virtual camera‘ in his hands – a square monitor screen – and pacing around an empty set, taking new shots. But when he looks through the camera screen, the stars of Avatar, Sam Worthington and Zoe Saldana, can be seen there, morphed into Na’vi, the blue deer-like creatures who populate the world of Pandora.
Looking through the screen, Cameron can walk around his actors and shoot from any angle. The actual performances took place months ago, and were captured on Cameron-designed 3D cameras, which stored the actors as a full-3D video inside a 68-terabyte computer in a ‘digital asset management system’.