A method of fairing parametric cubic B_spline curves and bicubic B_spline surfaces is presented. The basic idea of the method is to reposition the control points by an optimization process.A new objectijve function pr...A method of fairing parametric cubic B_spline curves and bicubic B_spline surfaces is presented. The basic idea of the method is to reposition the control points by an optimization process.A new objectijve function presented is based on the variation of the third order derivatives of the cubic B_spline curves and bicubic B_spline surfaces at the nodes. The curves and surfaces faired using this method tend to possess curvature continuities. The numerical examples show that the effect of this method is acceptable.展开更多
A novel method is produced to evaluate the energy of the Catmull-Clark subdivision surface including extraordinary points in the control mesh. A closed-form analytic formula for thin plate energy of the Catmull-Clark ...A novel method is produced to evaluate the energy of the Catmull-Clark subdivision surface including extraordinary points in the control mesh. A closed-form analytic formula for thin plate energy of the Catmull-Clark subdivision surface of arbitrary topology is derived through translating the Catmull-Clark subdivision surface into bi-cubic B-spline surface pieces. Using this method, both the membrane energy and the thin plate energy can be evaluated without requiring recursive subdivision. Therefore, it is more efficient and more accurate than the existing methods for calculating the energy of the Catmull-Clark subdivision surface with arbitrary topology. The example of surface fairing demonstrates that this method is efficient and successful for evaluating the energy of subdivision surfaces.展开更多
文摘A method of fairing parametric cubic B_spline curves and bicubic B_spline surfaces is presented. The basic idea of the method is to reposition the control points by an optimization process.A new objectijve function presented is based on the variation of the third order derivatives of the cubic B_spline curves and bicubic B_spline surfaces at the nodes. The curves and surfaces faired using this method tend to possess curvature continuities. The numerical examples show that the effect of this method is acceptable.
文摘A novel method is produced to evaluate the energy of the Catmull-Clark subdivision surface including extraordinary points in the control mesh. A closed-form analytic formula for thin plate energy of the Catmull-Clark subdivision surface of arbitrary topology is derived through translating the Catmull-Clark subdivision surface into bi-cubic B-spline surface pieces. Using this method, both the membrane energy and the thin plate energy can be evaluated without requiring recursive subdivision. Therefore, it is more efficient and more accurate than the existing methods for calculating the energy of the Catmull-Clark subdivision surface with arbitrary topology. The example of surface fairing demonstrates that this method is efficient and successful for evaluating the energy of subdivision surfaces.
