An Apple patent (number 8300055) has appeared at the U.S. Patent & Trademark Office and shows that Apple is working on an user interface for controlling three-dimensional animation of an object.
Per the patent a user can control the animation of an object via an interface that includes a control area and a user-manipulable control element. The control area includes an ellipse. The user-manipulable control element includes a three-dimensional arrow with a straight body, a three-dimensional arrow with a curved body, or a sphere. In one embodiment, the interface includes a virtual trackball that is used to manipulate the user-manipulable control element.
Here's Apple's background on the invention: "In the last few decades, computers and software have been used to animate objects. Initially, animation software was complicated and difficult to use. A user was generally required to interact with objects using a low level of abstraction. For example, a user would...| Read more »