Why You Should Pretend King Kong is a Bowling Ball: Physics and Animation
Jason Martinsen, Lead Animator at Sony Pictures Imageworks, explains how the mechanics of a bouncing ball is a key lesson to understanding animation. The best way to prove this? By pretending King Kong is a bowling ball. Read on for a quick physics lesson and make sure to watch Jason's frame-by-frame breakdown of a T-Rex fight scene from the movie "King Kong."
The Bouncing Ball: A Lesson in Physics
One of the most important principles of animation is the bouncing ball, or squash and stretch. As Jason explains, this helps animators learn how to exaggerate movement. When a tennis ball hits the ground, it doesn't just stop or bounce forever with a robotic, even cadence. That would entirely defeat the purpose of most sports. The same goes for animation.
When a ball touches the ground, it sinks in before springing back up into the air, slowing down as it loses velocity and reaches its peak. When it reaches the highest point, it slows down slightly and enjoys some hang time before accelerating back toward the ground. The ball has different behavior at all stages.
Looking for an intro to animation? Check out CGMA course Animation for Beginners
Applications: Weight Matters
When applying the bouncing ball technique to your character's movement, it's important to factor in the character's weight. If your character is a flea, as Jason demonstrates in the video below, it's not going to sink into the ground very much and will have a lot of airborne hang time.
On the other hand, something heavy, like King Kong, would behave completely differently. Instead of bouncing like a tennis ball, King Kong would hit the surface and roll like a bowling ball. Once he gains momentum, he'll need a lot of force to stop him (say, for example, two giant T-Rexes).
Learn to make your own character movement in CGMA course Animation Foundation 101
Animation Analysis: Jason's Frame By Frame
To see how the bouncing ball method can explain the movement of both a carnival flea AND a humongous angry ape, watch Jason's animation analysis below.
RELATED LINKS
Looking for an intro to animation? Check out CGMA course Animation for Beginners
Learn to make your own character movement in CGMA course Animation Foundation 101
Dive into the mechanics of animation in Intro to Animation in Maya
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