Digital Wizardry Department

In his new movie, "The Curious Case of Benjamin Button," Brad Pitt's Benjamin is completely computer generated - from the neck-up, for the movie's first 52 minutes.

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

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.

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

Benjamin Button also uses "Contour" developed by pioneering Silicon Valley company Rearden.

Contour has the actor's face covered in glow-in-the-dark makeup which is then digitally filmed by multiple cameras while lit by strobes, capturing facial data in fine detail.

The footage is then melded together into a single composite before the computer-animated boffins get to work on taking Brad back to his future - and narrowing the increasingly fine line between acting in front of the camera and animating behind it.

Source: CBS Evening News and the New Zealand Herald