CONSTRUCTING MULTILOOPED SURFACES BY LOOP JOINING

The objective of this research is to develop a surface joining method for constructing multi-looped surfaces. Based on this method, surfaces can be self-joined or inter-joined on loops to construct multi-looped surfaces. A loop is a continuous and closed boundary on a surface. By constructing one or several single-looped B-spline surfaces, multi-lo oped surfaces are constructed through loop joining of boundary curve s egments. Loop joining is completed by merging the control points on th e surface boundaries of B-spline surfaces. With the merging of data st ructures simultaneously, the consistencies of geometry and topology ar e kept in the surface model. The proposed method for constructing mult i-looped surfaces has the advantages that it is conceptually explicit, simple for user understanding and easy for system programming, and th ere is no computation of surface/surface intersections involved, thus no numerical solutions for nonlinear equations are required.