James Cameron Takes MTV 'Behind The Screen' On 'Avatar'

Show also looks at 'Sherlock Holmes,' 'Dinner for Schmucks' and 'The Other Guys.'

How did he do it? Seriously. How in the world did James Cameron take an actor in a skintight suit with wires strapped to his body and motion-sensing dots stuck to his face and — presto! — turn him into a highly realistic blue alien bouncing around a lush planet in "Avatar"? We've seen motion-capture films before, but nothing that looks half as impressive as this.

So it really does seem like a sort of wand-waving magic, and to help unlock the mystery behind this enchanted, CGI form of moviemaking, we enlisted the man himself. During MTV's "Behind the Screen" show on Wednesday afternoon (December 16), Cameron sat down at his Hollywood mixing stage to walk us through the creation of one killer action sequence.

"I think that's how I've managed to stay successful as a filmmaker, by basically giving people the stuff I would have wanted when I was 14 or 15 years old," the director said.

But the inside scoop on "Avatar" was only one part of a packed half-hour of exclusive looks into some of the most anticipated movies of 2009 and 2010. We debuted a brand-new clip from Robert Downey Jr.'s "Sherlock Holmes," featuring the wily detective in a brutal battle against a ginormous foe. We also journeyed to the sets of two upcoming comedies for the first-ever looks at these productions. First, we brought you Steve Carell and Paul Rudd's "Dinner for Schmucks." This is the first time these two funnymen have appeared together since 2005's "The 40-Year-Old Virgin," and they were pumped about it.

"Paul has the ability to be very handsome and yet be ridiculous at the same time," Carell said.

From there, we made a stop on the set of the action comedy, "The Other Guys," starring Will Ferrell, Mark Wahlberg, Dwayne Johnson and Samuel L. Jackson. As Ferrell gave us a tour and joked that the entire set was in fact a green-screen concoction, Jackson joked, "We use more lead than anyone in the history of the LAPD! Our gun fights are legendary!"

As "Behind the Screen" moved from comedies to action flicks and back again, we kept returning to Cameron's "Avatar." Comparing the challenge of the film to a Rubik's cube, the director explained how he takes the motion-captured footage of his stars and sends it to the venerable New Zealand visual-effects house Weta Digital for a sort of photorealistic, computer-generated casing to be swathed over the actors' forms. Months and thousands of man hours later, the images begin to look like the breathtakingly beautiful scenes that have garnered so much early praise from critics.

"He's not a dictator, he's a collaborator," said star Sam Worthington. "He's not a leader who stands on a hill with a bullhorn. He gets in the trench with you and fights alongside you every step of the way."

That journey has led them all to make a movie quite possibly unlike any other ever made. Even the former Terminator and current governor of California himself, who has worked with Cameron on three films, was blown away.

"When Arnold Schwarzenegger saw the film," revealed Cameron, "he said, 'It's an emotional spectacle.' "

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