Warping to enhance 3D user interfaces

Cartoon animation techniques have previously been used to enhance the illusion of direct manipulation in 2D graphical user interfaces. In particular, animation may be used to convey a feeling of substance to the objects being manipulated by the user. The paper presents an expansion of this concept to 3D graphical object manipulation. A standard set of 3D direct manipulation operations have been extended to include animated visual feedback to add substance, operation cues for the user and constraint visualisation. Visual feedback effects using 3D warping can substitute for haptic feedback, squashing of an object when pressed against a wall, or stretching of an object to shown frictional forces. Finally, a pinning effect is explored for multiple users manipulating a common object in a collaborative environment.