There are few certain formulas for Hollywood success, but one of those is:
Will Smith + action-oriented script + visual effects = a great movie-going experience.
This is the plan behind I Am Legend, the post-apocalyptic action-thriller starring Smith as Robert Neville, a brilliant scientist who appears to be the last man on earth. Neville lives in a New York City decimated by a man-made and seemingly incurable plague to which he is somehow immune. Neville is driven to find a way to use his own immunity to reverse the effects of the virus, but he must do it before the mutant victims of the plague—the infected—stop him. Neville is outnumbered and running out of time.
Like any action movie, I Am Legend takes advantage of cutting-edge visual effects techniques like motion capture. Using motion capture to generate realistic movements for animated characters has become a staple of movie production nowadays. Motion capture is a technique to digitally capture the movements of people and objects and then to use them as the basis for animating characters. Motion capture can greatly reduce the time needed to create ultra-realistic movement and by compositing animated characters into live-action shots, filmmakers have greater flexibility in choreographing large-scale action scenes and can depict “stunts” that would be too difficult or dangerous to attempt with live action.
For I Am Legend the motion capture team from Sony Pictures Imageworks tried something different. Instead of working from a detailed shot list to produce specific movements to be used in preplanned shots, the motion capture team focused on developing a library of movements that could be edited, turned into animation, and combined with the live-action shots later in the production.
With only a small crew, the motion capture team spent a lot of effort at the beginning of the production of I Am Legend focused on capturing a variety of character movements, from the run of the mill walking, running, and jumping, to rather extreme stunts like falling over moving cars and being tossed about by explosions.
Later on, when production on the film proper was underway, the animation team would use these motion capture sequences to quickly create animated scenes. To do this, the motion capture and animation crews would need systems capable of displaying the complex animations in real time, so that they could provide a fast response to the director and give him options during post-production.