Putting a teenage boy and an adult Bengal tiger together in an enclosed space, such as the 20-foot lifeboat that is one of the few settings of "Life of Pi," is a dangerous proposition. So it shouldn't come as a surprise that 17-year-old star Suraj Sharma, who played Pi, was never actually in the boat with a live tiger.

"No, that never happened," Sharma told NextMovie of sharing the boat. Instead, he studied his massive, furry co-stars in their cages, and watched videos of their movement online. "I would watch them be trained and stuff like that."

"We didn't want our actor to get eaten," visual effects supervisor Bill Westenhofer told the New York Times."

Four real tigers were used in the production, for reference and motion capture, as well as for actual pivotal scenes. Including footage of actual tigers forced the effects team to make their digital tigers look realistic enough so as to be indistinguishable from the actual tigers.

"It set our bar high for CGI," Westenhofer said. "We couldn't cheat at all. It pushed the artists to go and deliver something that's never been done before, something as photo-real as anyone has ever done with an animal."

For example, for a scene in which the tiger, Richard Parker, swims in the water and can't get back onto the boat without Pi's help, a real tiger was used. In a scene where Richard Parker swipes at Pi from under a tarp, digital effects were used.

"You can't film it for real," director Ang Lee said in a making-of  featurette of the need for a CGI tiger.

Watch a production featurette all about Richard Parker, below.