2001 a space odyssey in Science Fiction Posted March 2, 2007 Very simple. They attached the camera to the set, which was shaped like a drum. The camera would have been right at the axis at one end of the drum, looking straight into the drum. and then they rotated the entire set, including the attached camera. The girl was never anything but straight up and down, and simply stepped in place at the bottom of the drum which was rotating beneath her. I hope that makes sense.