Advanced Head Rigs: Joysticks 'n' Sliders
Joystick controllers are commonly used in 2D or 3D character rigging for facial animation. With this tool, you simply set five consecutive keyframes to represent your origin, right, left, top, and bottom extremes. With those layers selected, you can instantly create a joystick controller on the stage that will interpolate between those extremes appropriately.
On this page I have gathered some examples of 2D illustrations that I've animated using "Joysticks 'n' Sliders". This technique comes in hand when wanting to create realistic facial movements quickly and efficiently. They're also a lot of fun to watch :)