It was the movie many wanted to make but nobody dared try?the film adaptation of F. Scott Fitzgerald's story "The Curious Case of Benjamin Button," about a man who is born old and ages backwards. The premise was as enticing as it was forbidding?how do you portray this character, the soul of the story, throughout his life without using gimmicks, multiple actors or not quite convincing animation (see Beowulf). After many years (and several directors) passed, the forces of technology and personality finally aligned in the form of Digital Domain, David Fincher, the Mova Contour Reality Capture system and a contingent of other artists and inventors. Their efforts represented a technical breakthrough that'll change filmmaking from now on, but the onscreen effect was invisible. Whether you loved the film's message of life, loss and love or the whole thing left you cold, you were evaluating it based on the story, not on the visual effects and that was Fincher's and Digital Domain's biggest achievement.
By 2004, DD and Fincher had started working on Button in earnest. That year they provided Paramount a one shot proof of concept video and got the green light (Ulbrich jokes that at that moment he excused himself to go and be sick?they actually had to do this thing now). The central challenge was to ensure that Pitt (rather than an animator's interpretation of Pitt) was actually playing the character throughout his life?from wizened man of 80-ish through his 70s and 60s to the actor's current age and beyond (Pitt played the character until he reached childhood. VFX company Lola provided "youthening" effects that made the actor appear onscreen as his unlined younger self). Given that mandate and the additional challenge of the difference in body size and type between Brad Pitt and the Benjamin character (who appears as a small, stooped old man in the early part of the film), traditional animation/head replacement techniques created too many opportunities for the character to fall into the dreaded "uncanny valley" (the creeps people get when looking at a being that appears almost but not quite human).
In a rather large nutshell, here's how they did it. The first thing to know: after the initial shots of the animatronic infant, the next 52 minutes of Pitt playing Benjamin do not contain any Pitt?it's animation (until the real actor appears in make-up on the tugboat bound for Russia. A total of 325 shots of animation. VFX shops Hydraulx and Asylum also contributed many elements to the film).
Fincher shot the film (with Viper cameras) using smaller, blue-hooded actors in place of Pitt. Make-up artist Rick Baker created three painstakingly detailed maquettes (models based on casts of Pitt's face) that represented the actor at ages 60, 70 and 80. DD then created digitized versions of the maquettes. Character supervisor Steve Preeg and Barba turned to what's known as FACS (Facial Action Coding System, a body of research by psychologist Dr. Paul Eckman that categorizes the full set of universal human expressions) as a starting point for Pitt's performance. DD used the Mova Contour system to capture Pitt performing that gamut of facial expressions. "When we first looked at doing this movie in 2004 we had something in our original R&D plan that was not dissimilar to what they built," says Barba. "When they presented their system we looked at each other like, 'they did it.'" The technology was still in its early days and Kreeg worked with the company to develop the system to fit Button's requirements. Mova's markerless system represented a significant advance in performance capture, creating a high def, "volumetric" representation of a face (or other surface). Performer's faces are covered in phosphorescent makeup and captured by a multi camera rig?this eliminates the sort of interpolation that happens with a system that uses a number of markers placed on the face to capture data.
DD is currently at work on projects that will advance the tech and systems used on Button. "It's a game changer," says Ulbrich. "It'll be difficult to do a less realistic character now." And yes, you will see the technology used in commercials. "With computer-based visuals there's a belief that anything is possible as long as you have enough time, money and resources," says Ulbrich. "In advertising there's just never enough. It's a big advantage for our advertising clients to have tools available to them that would otherwise be cost and time prohibitive to develop for a single spot or campaign."