Study on constructing the 3D yarn model by B-spline surface(partI): construction of the 3D yarn model with different cross sections

In order to construct a universal 3D yarn model with different cross sections,the design methods of yarns with such cross sections as circle,running path,convex mirror,rectangle,and bowel by B-spline curve were investigated.Then,the B-spline surface was used to connect several sections of yarns and construct a single yarn having different cross sections 3D model.