Automatic viewing control for 3D direct manipulation

Abstract

This paper describes a technique for augmenting the process of 3D direct manipulation by automatically finding an effective placement for the virtual camera. Many of the best techniques for direct manipulation of 3D geometric objects are sensitive to the angle of view, and can thus require that the user coordinate the placement of the viewpoint during the manipulation process. In some cases, this process can be automated. This means that the system can automatically avoid degenerate situations in which translations and rotations are difficult to perform. The system can also select viewpoints and viewing angles which make the object being manipulated visible, ensuring that it is not obstructed by other objects.