System and Computer-Implemented Method for Modeling the Three-Dimensional Shape of An Object by Shading of a Two-Dimensional Image of the Object

A computer program product for use in connection with a computer to provide a computer graphics system for generating a geometrical model representing geometry of at least a portion of a surface of a corresponding three-dimensional object from shape information provided by an operator in connection with a two-dimensional image of the object, the image representing the object as projected onto an image plane, the computer program product comprising a computer readable medium having encoded thereon:

• A. first computer executable instructions encoded on the medium and executable by the computer to enable the computer to receive shape information provided by the operator in connection with a selected portion of the two-dimensional image;
• B. second computer executable instructions encoded on the medium and executable by the computer to enable the computer to receive the shape information from an operator input device usable by the operator to provide the shape information, the shape information including shading information, the shading information representing a change in brightness level of the selected portion of the image, the shading information creating a two-dimensional representation of a three-dimensional change of shape of the corresponding three-dimensional object in the selected portion of the image, and to generate in response thereto an updated three-dimensional geometrical model of the three-dimensional object, the second computer executable instructions further being executable to enable the computer to use the shading information to determine at least one geometrical feature of the updated geometrical model, the updated three-dimensional geometrical model of the corresponding three-dimensional object including a three-dimensional change of shape corresponding to the two-dimensional representation of the three-dimensional change of shape in the selected portion of the image;
• and
• C. third computer executable instructions encoded on the medium and executable by the computer to enable the computer to display the image of the object as defined by the updated geometrical model.