服装CAD制版系统中曲线绘制自动化方法研究

Research on Automatic Method of Curves Drawing in Garment CAD Pattern System

摘要: 为了自动绘制服装结构曲线，分析制版师在服装CAD制版系统中手工绘制曲线的过程，总结出每条曲线是经过四个固定点的光滑曲线；提出基于贝塞尔曲线控制点的曲线自动绘制方法；进而针对贝塞尔曲线的控制点不在曲线上并且计算复杂的问题，提出一种基于改进解方程组法的控制点计算方法和一种基于梯度下降法的控制点计算方法，对二者进行了对比。实验结果表明：文中2种方法所拟合出的服装结构曲线都符合服装结构设计精度的要求，改进解方程组法在时间成本和算法复杂度方面均优于梯度下降法；梯度下降法可通过调整初始参数计算得到精度更高的控制点，但其消耗的时间成本巨大。改进解方程组法作为首选方法，梯度下降法作为优化方法。

Abstract: In the garment CAD pattern system, the garment structure curve was manually drawn by the pat-tern maker and adjusted by his experience and design principles. Each curve took several operations to generate. Bézier curves and NURBS curves based curve drawing methods need to calculate control points. These control points were not on the curve and were computationally complex. In order to make curve drawing not depend on the manual operations of the pattern maker, by studying the drawing process of garment structure curve, an automatic method of curve drawing based on control points of Bézier curves was proposed. The method only relies on several fixed points of the curve and can calculate the control points of the curve automatically; the fixed points are obtained through the design principle of the garment structure curve. Thus, garment structure curve drawing automation is realized; the method can be used for garment CAD pattern system based on parameters design to improve the efficiency of garment patterning.