Behind Brad Pitt's Digital Transformation

Brad Pitt stars as Benjamin Button - The Curious Case of Benjamin Button
Brad Pitt stars as Benjamin Button - The Curious Case of Benjamin Button, 2008.
Paramount Pictures

He's one of Hollywood's most bankable and best-looking stars.

And in his new movie, "The Curious Case of Benjamin Button," Brad Pitt doesn't look a day over seventy five, CBS News anchor Katie Couric reports.

Based on a short story by F. Scott Fitzgerald, "Benjamin Button" is about a man born in his '80s who ages backwards.

In the film, Benjamin says, "What if I told ya that I wasn't getting older, but getting' younger than everybody else?"

And the film's 45-year-old leading man insisted on playing the part from the cradle to the grave.

In an exclusive interview, Pitt explained: "Before if you were attempting a film like this, you would have to plug in different actors at different ages. Sometimes it connects, sometimes it doesn't. And in this, we got to drive the performance all the way.

So, like many aging stars, Pitt had some work done. In fact, for the movie's first 52 minutes, Benjamin is completely computer generated - from the neck-up.

"For all intents and purposes, we effectively created a digital puppet of Brad that Brad could operate," said Ed Ulbrich, executive VP of production at Los Angeles' Digital Domain.

Visual effects artists at Digital Domain began by asking Pitt to make funny faces for their cameras, creating what they called the Brad Pitt Emotional Library.

"You just spend the day being a jackass doing this or doing this," Pitt said, making faces to demonstrate. "Trying to map all my facial expressions, muscles. We did that for a few days."

Meanwhile, a series of other actors with Benjamin's physical characteristics stood in for Pitt on set.

Visual effects work being what it is, the blue hoods meant they could check their vanity at the soundstage door.

"With the blue hood, it allows us to erase the head fairly easily and then apply the computer generated version of Brad on to that body," Ulbrich said.

Months after principal filming was finished, Pitt delivered his performance, while watching the scene on a monitor.

"I see it on screen and I'm playing off that, and I'm reacting to that," he said.

Then, using 3-D computer models, aged to perfection and loaded with that library of Brad-isms, animators could finesse Pitt's digital performance to make a perfect copy of the original.

"What was important to us in this process was that the emotions that Brad carries as an actor come through Benjamin," Ulbrich said.

Read more of the CBS News Exclusive interview with Brad Pitt.
Watch clip: The "Brad Pitt Emotional Library"
And see what director David Fincher had to say about transforming his star to an old man on screen.
And to button it all up, they virtually stitched the digital head on the actor's real body.

Brad Pitt may not be ready for the old folks' home yet, but being an armchair actor is something he could get used to.

"It's really quite freeing," he said. "I'd like to do all films that say."