| 摘要 |
The invention relates to a method for embossing a watermark into a model of a linear or planar shape, especially a non-uniform rational B-splines (NURBS) model. Said model comprises a plurality of splines, the combination of which forms the shape. Control points (P) are assigned to the splines such that a course of the respectively associated spline can be modified and thus be controlled by changing the position of the control points (P) and/or weights of the control points. Furthermore, nodes which are located in a section of the shape that is formed by the respectively associated spline are allocated to the splines. In order to change the shape (the modified curve runs through point C<SUB>mod</SUB>) when a watermark is embossed into the model, the position of at least one control point is modified, the weight by which a control point affects the shape and thus influences at least one area of the shape is modified, and/or an additional control point is inserted into the model. At least one additional node is inserted into the model (new node at u = 1.1875 on the modified curve) in order to obtain information on how the change of the shape can be reversed. |
