Richard Williams' "Animator's Survival Kit" talks a lot about the topic of "breaking the joints." I'm wondering if this is a technique that is exclusive to 2D animation or if it is used in 3D animation as well?
If so, can you elaborate on how it is used and maybe provide some specific examples?
This question comes from Jason. Great question! Thanks for coming by the blog Jason!
Breaking of joints, also often called "Sequential breaking of joints," or "successive breaking of joints," is basically a way of looking at your body mechanics as though it were a chain of events, or a series of joints where each joint affects the joint beneath it (and/or above it).
The classic example of this is in looking at a blade of grass or a cracking whip, where you could imagine the blade of grass blowing in the wind as being made up of a bunch of tiny sections which affect and move each other. Same with the whip. You could think of the tip of the whip as the very end of a series of "sections" or "joints," that snake all the way back up through the whip, into the hand, the wrist, the forearm, the upper arm, the shoulder, the chest, down the spine, and all the way to the hips. The hips are probably originating the whip action, and it propagates upward and outward from there, building in force and power until the tip of that whip actually breaks the sound barrier and makes that loud cracking sound.
The "blade of grass blowing in the wind" works the same way our spine might work as we're riding a bucking horse or doing any one of a huge list of actions that would originate in our hips (the base of the "blade of grass") and move upward with each section or "joint," having overlapped timing and creating follow-through action.
This idea is essential to creating a strong sense of internal force in your body mechanics, as well as nice follow-through, strong arcs, anticipation, weight, etc. It's one of the most fundamental concepts of animation and affects any number of other animation principles, so it's definitely something to continue investigating!