Mark Mayerson

Writer, Cartoonist, Sculptor

Motion Capture
(November 18, 2007)

The differences between motion capture and animation are wider than people think. It's not simply a question of technique.

With motion capture, motion exists in the real world. It gets sampled and then applied to a computer character. With animation, the motion does not exist in the real world. It is constructed and only exists when the images are rapidly displayed, creating the illusion of motion. That describes the process.

There are several differences philosophically, however. Motion capture seeks to convince an audience through the accumulation of detail. When it falls short -- when it is criticized for looking like a waxworks -- it is due to insufficient detail in the motion. Therefore, the goal of motion capture is to increase detail to the point where it is indistinguishable from live action. As Ken Ralston says,

Trust me, when you’re sitting in dailies talking about Anthony Hopkins’s armpit hair for an hour, you know there’s a lot of effort that goes into every pore of the skin, into every eye and eyebrow. It’s a massive puzzle that has to be broken apart and then put back together again.

By contrast, good animation seeks to eliminate unnecessary detail in order to arrive at the expressive essence of a motion. Motion capture concerns itself with addition; animation with subtraction.

If animators look down on motion capture technicians, it is because of the relationship that these two groups have with essence. If there is an essence in a motion captured performance, it comes from the actor. The job of the motion capture technicians is to accurately reproduce it. Any animated additions they make are a result of the technology's shortcomings or the director's change of heart. By contrast, an animator, if successful, creates the essence of the motion. This is no small distinction. There is a world of difference between reproduction and creation.