Physical reality
The third major approach to computer animation is called simulation. The goal here is to figure out how the human body can move based on the laws of physics and what the muscles do. While keyframing starts with drawings and motion capture starts with actual human movement, simulation starts with computer models of the body.
Your hand, for example, has a certain mass, and is connected by the wrist to your forearm, which in turn has a certain mass and is connected to the... In other words, the hip bone's connected to the thigh bone, and the thigh bone's connected to the leg bone...
Once the software can represent all possible human movements, a control system enters the picture to represent how the brain is instructing the muscles to move the whole heap of bones.
The result is software that can be directed -- with some effort -- to simulate such human actions as running [QuickTime, 1560K].
Simulation can also be handy for animating crowds, and for representing water and clothing. Here's how it can animate a foot splashing through a puddle [QuickTime, 737K].
Eventually, simulation could help program humanoid robots -- a field that's far behind the wheeled variety.
Got any idea where this thing is going?
