Patent ID: 6392645
Filing Date: 2002-05-21
Classification: G06T

Abstract:
A computer program product which provides a visual depiction of a three dimensional object upon a display device, the three dimensional object comprising plural solid shapes, the program comprising computer readable code stored in a memory, the computer readable code being executable on a processor to which information is input via a user input device;wherein, in depicting the three dimensional object, the program uses a feature-based data structure for at least one of the solid shapes comprising the three dimensional object; and wherein, when input from the user input device designates a designated solid shape, the computer program product creates a direct face data structure for the designated solid shape by performing the steps of: generating a boundary representation for the D-Shape; using a topology-changeable local operation to generate a modified boundary representation for the D-Shape; and then as a separate step modifying the history of the three dimensional object.