【作者】 宋利伟；

【导师】 罗中先； 戴跃洪；

【作者基本信息】 西华大学 ， 机械设计及理论， 2007， 硕士

【摘要】 三维参数化特征建模是当今三维CAD的主流技术，它可以大大提高设计效率，降低设计成本。而三维参数化设计的基本流程是：先绘制一个二维草图，通过添加约束和尺寸，再借助于尺寸驱动来实现图形的参数化，获得所需二维轮廓设计，然后通过拉伸或回转等生成三维实体模型。可见二维参数化草图技术是三维参数化特征建模的重要基础。本文对二维参数化草图技术进行了系统的研究，在．Net平台上，使用GDI+图形库进行了参数化草图器的开发，主要取得了以下四个方面的进展：(1)对草图的基本图元进行了相应图元类的设计，用GDI+图形库实现了各基本图元的生成。(2)对各类图元的尺寸标注构造算法进行了研究，在程序中实现了各类图元的尺寸标注。(3)结合快速尺寸驱动方法和简单几何推理算法，提出基于简单推理的约束求解算法。(4)针对这种基于简单推理的约束求解方法，建立一个由四层链表组成的存储结构，能很好地支持草图在基于简单推理的约束求解算法下的尺寸驱动。更多还原

【Abstract】 Three-dimensional parametric feature modeling is the main technology of today’s three-dimensional CAD. It greatly improves the design efficiency and reduces the design cost. The basic flow of the three-dimensional parametric design is as follows: at first,a two-dimensional sketch is drawn,and a needed outline can be got through adding constraints and modifing parameters of the sketch. Then a three-dimensional solid model can be created through extruding or revolving. Therefore the two-dimensional parametric sketch technology is an important foundation of three-dimensional parametric feature modeling.This article mainly focuses on the system research about the two-dimensional parametric schetch technology. We developed the sketch software by using the GDI+ graphic warehouse, and mainly launch the article on the four questions, as follow:(1) The thesis designes the corresponding graphic elements’ abstract class, and realized the graphic drawing by using the GDI+.(2) Has conducted the research to each kind of the graphic dimension algorithm, has realized each kind of the graphic dimension in the procedure (3) Unifying the fast dimension driving method and the simple geometric reasoning algorithm, we proposed a new algorithm named ’based on the simple inference restraintsolution algorithm’.(4) In view of this new algorith, we established the storing structure which is composed by four storing chains, can support the the dimension driven arithmetic based on the new algorithem.更多还原