The characters' movements were based on real actors wearing special motion-capture sensors that cameras could track.
Now, researchers from New York University have tried the same thing with Olympic athletes -- taping sensors to the swimmer Dana Vollmer and the diver Abby Johnston.
They set up a company called Manhattan Mocap, and shot video of the athletes from myriad angles. They produced some beautiful pieces of computer animation -- but the real purpose was to see how the swimmers moved through the water and how they could improve.
"I'm a very visual learner; I watch a lot of video," said Johnston. "So I'm excited to see different angles, and I think that will enhance my training and give me a different perspective on what goes on while I'm diving."
They found that while swimmers need a strong kick and powerful stroke, what really matters is how they move through the water. Vollmer, they concluded, swims a bit like a dolphin, shimmying along with very little drag.
If you saw Olympic swimming events, you could see the effect on how world-class athletes have altered their approach over time. When Michael Phelps, for instance, finished a turn, he would stay under the water for as long as he could, seeming to wriggle along. It was as fast -- and took less energy -- than swimming on the surface.
Similarly, Johnston, the diver, said she learned to refine her technique as she watched herself from myriad angles. The motion-capture system, combining input from several cameras, could show her from almost any point of view.
"There's really small changes that can be made that will perfect the dive," said Johnston. "So being able to see the dive from different angles and make small adjustments, I think, will be really, really helpful."
Did the video pay off? Well, the athletes were very good to begin with. Vollmer took home three gold medals; Johnston won a silver.