Designing A 3D Modeled Object

Computer program recordable on a data storage medium and comprising instructions for performing a computer-implemented method for designing a 3D modeled object, wherein the method comprises the steps of:

• providing a base mesh controlling a subdivision surface, the subdivision surface modeling the 3D modeled object;
• providing a polyline consisting of connected edges of the base mesh;
• defining a smooth portion of the polyline comprising an extremity of the polyline and a sharp portion of the polyline upstream the smooth portion;
• and
• converting faces of the mesh adjacent to the polyline into parametric patches approximating the subdivision surface, in which the patches have a G0 connection across the sharp portion of the polyline, and the patches have a Gi connection across the smooth portion of the polyline, where i is an integer higher or equal to 1.

A CAD system comprising a processor coupled to a memory and a graphical user interface, the memory having recorded thereon a computer program for performing a computer-implemented method for designing a 3D modeled object, wherein the method comprises the steps of:

• providing a base mesh controlling a subdivision surface, the subdivision surface modeling the 3D modeled object;
• providing a polyline consisting of connected edges of the base mesh;
• defining a smooth portion of the polyline comprising an extremity of the polyline and a sharp portion of the polyline upstream the smooth portion;
• and
• converting faces of the mesh adjacent to the polyline into parametric patches approximating the subdivision surface, in which the patches have a G0 connection across the sharp portion of the polyline, and the patches have a Gi connection across the smooth portion of the polyline, where i is an integer higher or equal to 1.