“We were in a machine that’s never been invented before,” Clooney said before lunch, near the stuffed polar bear at the Explorer’s Club in Manhattan, where the intimate event was held. “They were the machines that they build cars on in Detroit, these old, giant machines where they flip you around in a bunch of different directions, and then the camera is on another machine like that, and it would flip around, so that your body and the camera were moving all at the same time.” Meaning the two actors were really moving, not simulating motion. “It was really disorienting,” Clooney said, laughing.
They got dizzy, and it was uncomfortably warm inside the space suits they wore. “Not as bad as the Batsuit, but just about,” Clooney said, laughing, referring to his 1997 Batman role.
Source: Vanity Fair