Inkwell was an animation system for 2D animators. This paper describes

both the motivations for and implementation of Inkwell.

Similar to Catmull, Litwinowicz combined recent ideas from other systems
-- with the goal to give 2D animators better control. His solution was a
system that included shape and timing control, digital filtering and
deformation and animation of textured regions.

Key ideas: Keyframing using a cubic spline to interpolate. Filtering to
smooth, overshoot or add "wiggle" to motion. Coons patches, used to
animate warped images. Cosine windows, to warp large groups of objects.


Contributions: A system to combine all of the key ideas together in one
place, and some empirical data as to how that system helped speed up
animators' work.

Applying Cartoon Animation Techniques to Graphical User Interfaces

They take the principals of 2D animation and apply them to UI's in order
to make widgets seem more massive. They do this in order to solve the
problem of UIs that don't seem to work like the real world, giving poor
feedback and so defying user's expectations.

In order to examine this problem, they built a prototype editor which they
could use to test whether their techniques were effective.

Key ideas: Smooth and realistic motion can help suspend a user's
disbelief. It also shifts the interpretation of a change in the UI to the
user^%G�%@ perception system, allowing their cognitive system to stay focused
on the task at hand. Gravity, inertia and stretching can signal to the
user constraints on an object that may otherwise not be obvious.

Contributions: In addition to these ideas, they contributed a user study
that showed what amount of animation users preferred. In most cases, they
seemed to validate the author's assumptions that a small amount of