The Polar Express —Performance Capture

All the characters in the motion picture Polar Express were created using what has been termed motion capture or performance capture.

In motion capture, an actor is fitted with a body suit covered with reflector dots so that a computer can record the details of his movement as he performs the role.

Polar Express used an integrated version of motion capture, attaching reflector dots to the performers’ body, face and scalp, allowing digital cameras to capture nuances of the performers’ facial movement. As actors perform on a blank stage, their body and facial movements are precisely recorded and entered into a computer. The captured performance, or generated motion, can then be applied to a computer modeled character, giving the digital character lifelike, subtle movements. In Polar Express,72 cameras were used to provide coverage for four actors and their facial and body markers—152 facial markers and 54 body markers per actor.

Using this technology, anyone can play any role. Indeed, in Polar Express, Tom Hanks played the conductor, the lead boy, the boy’s father, a hobo, and Santa. Only the conductor was recognizably Hanks, but the designers found it useful to mimic some aspects of the actor in other characters. For example, the boy was given eyebrows like Hanks’ because he uses his eyebrows in acting. Using performance capture, the director can have a camera anywhere, rather than positioning it in key places, filming the action, and then moving the camera. The problem with the technique, at present, is that the characters do not appear truly human. One review said the characters looked laminated or embalmed. If the eyes are the windows to the soul, “the computer animator cannot yet open that window.” Another said that the technique “leaches [Hanks’] trademark charm and everyday humanity off the screen,” and that the characters appear remote and zombie-like, with dead eyes and deadened features. A third commented that the computer generated characters had been criticized for looking “vacant,” or “creepy.” Nevertheless, performance capture has substantial uses today and may well be improved. The captured animation and the computer modeled characters are capable of being used in new films and other new contexts, together or separately.

Digital Actors and Copyright - Part Two