Abstract: In order to improve the whole quality of reconstruction model and reflect the original design intention, theory and method are proposed to solve the constraint reconstruction problem of 2D symmetry geometry model. Firstly, the parametric points are constructed: the reflectional symmetry points are mirrored through the symmetry axis, and the rotational symmetry points are rotated about the rotational center. Secondly, the constraints between curves and the boundary constraints of the symmetry model are identified and handled. Finally, the objective fitting function with constraints is constructed based on objective points which include the parametric and the basic points. The optimization problem is recursively solved using L-M method. The examples show that the results of reconstruction not only satisfy the original constraints but keep rigid symmetric.

Key words: Parameterization, Reverse engineering, Symmetry