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

Abstract

A computer graphics system generates a three-dimensional model of an object in an interactive manner under control of an operator. An initial model for the object to be modeled is displayed to the operator as illuminated from a particular illumination direction and projected onto an image plane. The operator can update shading of a pixel on the image plane, and, based on the updated shading, the computer graphics system generates an updated normal vector for the updated pixel, which identities the normal of the surface of the object projected onto the updated pixel. Using the updated normal vector field and a height field, which represents the height of the respective portion of the object as projected onto the respective pixels of the image plane, the computer graphics system generates an updated height value for the updated pixel, thereby to update the height field.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application for patent is a Continuation of U.S. patent application Ser. No. 11 / 536,345 filed Sep. 28, 2006 (Atty. Dkt. MENT-003D1-CON), which is a Continuation of U.S. patent application Ser. No. 10 / 795,704 filed Mar. 5, 2004 (MENT-003D1), which is a Divisional of U.S. patent application Ser. No. 09 / 027,175 filed Feb. 20, 1998 (MENT-003) (issued as U.S. Pat. No. 6,724,383 on Apr. 20, 2004), which claims the priority benefit of U.S. Provisional Patent App. 60 / 038,888 filed Feb. 21, 1997, each of which is incorporated herein by reference. Also incorporated herein by reference is “The Shape-By-Shading Modeler,” a paper by Rolf Herken and Tom-Michael Thamm, attached hereto as an Appendix.FIELD OF THE INVENTION[0002]The invention relates generally to the field of computer graphics, computer-aided geometric design and the like, and more particularly to generating a three-dimensional model of an object.BACKGROUND OF THE INVENTION[0003]In c...

AI Technical Summary

Benefits of technology

"The invention is a computer graphics system that allows an operator to create a three-dimensional model of an object by shading it in real-time. The system uses an initial model of the object and displays it to the operator, who can adjust the shading to match their mental image. The operator can also add or remove shading at different points in the image and adjust the position and orientation of the object for better shading. The system avoids the need for solving partial differential equations and allows for conventional computer graphics operations, such as rotation and scaling, to be performed. The final model can be saved or updated further. Overall, the invention provides a more intuitive and efficient way to create and modify three-dimensional models of objects."

Problems solved by technology

Since images can be noisy and the assumptions noted above are sometimes not perfectly satisfied, there may be no solution using this methodology, and in any case there will be no unique solution.

Images