提出了一种新颖的自由曲面上影射曲线的计算方法，该方法通过把沿任意方向曲线向曲面影射的问题转化为一系列等参数曲线与一般柱面的求交问题，从而把三维模型空间转变到二维的参数空间，提高了计算效率。由于采用了ＮＵＲＢＳ方法，使所有的曲线曲面表示都统一在同一种形式之下，更有利于后续的处理工作。 A novel method of calculating the projection curve on a free-form surface is proposed. The method transforms the problem of mapping the surface along an arbitrary direction to a curved surface into a series of cross-parametric curves and the intersection of a general cylinder and the transformation of the three-dimensional model space To two-dimensional parameter space, improve the computational efficiency. As a result of the NURBS method, all the curves and surface representations are unified in the same form, more conducive to follow-up processing.