Join George Maestri for an in-depth discussion in this video Understanding forces and motion, part of Animation Foundations: Fundamentals.
As an animator, your job is to move things. So, understanding how things move is important. Our first law of motion is that an object at rest tends to stay at rest. This means that an object will simply sit still until something gets it moving. And once it is moving, it will continue to move until another force acts upon it. So, force creates motion. Our second law is that, when a force acts upon an object, that object's velocity will change at an increasing rate.
This change is called acceleration. Acceleration can work both ways. You can accelerate something to a faster speed or you can accelerate it in the opposite direction to slow it down. When an object accelerates, it simply means that the object moves faster and faster until the force is removed. Forces can also be used to accelerate an object to move it in a different direction. And once the force is removed the object tends to stay in motion and the first law takes over. The object moves in a straight line at a constant velocity. The third law of motion is that all forces exist in pairs. If I push on something that thing also pushes back. So, for every action, there's an equal and opposite reaction. For example, take two objects that strike each other. The object that is moving exerts a force on the stationary object, causing it to accelerate and move.
But the original object also gets a push from the object that hits, causing it to move back as well. The distance that the original object moves back is dependent on it's mass, the heavier the object, the less it will move. To sum up, forces are what move objects. Object accelerate when force is applied and objects also push back when force is applied. Heavier objects resist motion more.
- Understanding forces and motion
- Working with center of mass
- Adjusting frame rates
- Understanding keys and keyframes
- Building animation paths
- Navigating the object hierarchy
- Staging an animation
- Animating to audio and music