基于NURBS曲面的经编针织物三维模型

3-D modeling for warp knitted fabric based on NURBS

为使经编针织物CAD系统具有更真实的模拟效果,给设计人员提供准确的工艺设计方案,使用NURBS曲线和曲面的方法建立经编针织物的三维结构模型,并利用保形保凸反算插值的方法,在基本型值点的基础上重构表示经编线圈曲线模型的控制多边形,精确地确定空间纱线的实际形态和位置,描绘出精确的空间曲线。借助于Visual C++和Open GL开发工具,在计算机上实现了经编针织物的三维仿真。由实现的基本经编针织物效果图可以知道,这种模型能达到较好的仿真效果。

In order to obtain more realistic simulation in warp knitting CAD system and provide more exact technologic design, it is necessary to develop a three-dimensional solid modeling of warp knitted structure and realize it on the computer screen. This article offered a 3-D solid model of the loop by using NURBS. By anti- calculating the control points of this model, the more exacted control polygon was gained and the real shape and position of space yarn can be described exactly. With program of Visual C ＋ ＋ and developing tools of Open GL, 3-D simulation of warp knitted fabric can be realized visually on computer screen. As shown in the simulated graphics of basic warp knitted fabrics, this modelling can achieve good simulation effect.