Supporting 3D warping visual feedback for virtual reality

Cartoon animation techniques have previously been used to enhance the illusion of direct manipulation in 2D graphical user interfaces. In particular, animation can convey a feeling of substance in the objects being manipulated by the user. The paper presents the expansion of this concept to 3D graphical objects manipulated in a virtual reality domain. Three effects using 3D warping are presented to provide visual feedback of objects interacting in virtual reality applications. These include squashing of an object when pressed against a wall, stretching of an object to show frictional forces, and finally, a pinning effect when multiple users manipulate a common object in a collaborative environment. The paper goes on to discuss a set of important implementation issues for building systems with 3D cartoon animation feedback.