This is an exercise in creating rig controls, and a potential basis for a number of animation studies. I plan on releasing the rig along with a small collection of rigged balls.
The rig’s controls are:
Root and main, controlling the overall armature at the armature origin and ball origin respectively.
Rotation, serves as main control for the ball’s rotation.
Stretch handles allow squashing from either end of the ball along the stretch axis.
Stretch axis Allows stretch axis to slide around under the surface of the ball, making it easier to bounce the ball off of walls without counter-animating rotation.
The rig can handle scaling of the root and main positional bones.