The master animators of Disney developed the 12 principles of animation for producing expressive
and stylized 2D animations.
Conceptually, these principles help an animator to develop a complex animation from simple understandable chunks.
For example, this animation is composed of four animation principles.
Squash and stretch, follow through, staging, and slow-in slow out.
Skuid is a sketching tool for crafting animated illustrations using the principles of animation.
We devise a set of motion design tools for stylized animation effects. Named amplifiers.
These amplifiers correspond to the principles of animation.
In this drawing, we sketch a bird, create an object by lassoing the strokes
and record a motion. The bird is cute, and it's now moving, but there is no life to it.
We activate the slow-in-slow-out principle, and the animation immediately exhibits the behavior.
We then apply squash-and-stretch, and control the strength of the amplifier.
Let's activate the follow through, and specify the rigid part of the bird.
The wings of the birds now exhibit follow through behavior.
Activating the staging amplifier displays the dynamic motion trails.
Now the bird looks lively and expressive!
In this example, this cute little guy is composed of two objects.
We first animate his tail.
For the main body, we specify the rigid parts
and the stationary parts.
We then activate the secondary motion amplifier, and make the tail secondary to the main body.
Now, as we animate the main body, the secondary motion adds more dimension to the animation.
Our approach is purely geometric, and works for freeform sketches,
requiring no skeletal information.
The Arcs amplifier dynamically deforms the drawing along the trajectory of the motion path
We can insert an additional slow-in slow out
effect by directly tapping on the motion path.
The Anticipation effect pulls the object backwards before the primary action to build momentum.
The default anticipation pose squashes the object backwards.
But, we can sketch the desired anticipation pose
to make the action more expressive.
A side-by-side comparison shows how much the amplifier adds to an animation.
One of our participants re-created his frame-by-frame hand-drawn 2D animation done 20 years ago
in a fraction of its original time.