Abstract:

The Gaussian parabolic line on the Gaussian map of the free-form surface alternatively intersects or is tangent to its boundary. An algorithm given byT. S. Smish and R. T. Farouki to determine the outermost boundary of the Gaussian map consideres barely the intersection. The limitations of the old algorithm is analyzed theoretically in this paper, and a better algorithm and its proof are given. At last,a computing example is offered.

Key words: free-form surface ;Gaussian map, Gaussian parabolic line