基于二维信息的虚拟立体建模技术的研究

【作者】 郗润平；

【导师】 翟正军；

【作者基本信息】 西北工业大学 ， 计算机应用技术， 2003， 硕士

【摘要】 在对新型产品的开发与研制中，常在立项研究和概念设计阶段就需要进行干涉检查、物性计算、机构分析、运动学和动力学分析、真实感显示等试验与测试。上述分析、试验、测试等过程都离不开对三维虚拟立体模型的建立与研究。 由三视图组成的工程图，是用二维信息完整地表达三维物体的通用工具。由于直接建立三维立体模型过程复杂，因此有必要在工程图与三维模型之间建立一种对应关系，自动地将二维工程图转换为三维立体模型。 一个三维形体可以认为是由一系列基本特征形体组合而成的，因此从二维信息建立三维模型的关键就是如何识别出二维信息中所包含的三维特征信息。 本文在介绍和分析前人有关三维立体重建的研究算法的主要思想及其优缺点的基础上，提出一种基于二维三视图DXF图形数据进行三维特征识别的三维虚拟立体建模方法。 通过对三视图的DXF图形数据的结构分析，获取了相关的二维图形信息，并按特征建模的要求对各视图的二维图元进行识别和分类，以利于三维特征的有效识别。 对DXF文件提供的数据进行预处理，对三视图进行自动分离，并确定投影中心，使得三维立体特征的识别难度降低，提高了算法的识别效率。 根据工程图的投影规则，制定出了基于二维工程图的三维立体特征识别的规则和过程，从体的角度，同时结合二维图元信息进行三维特征识别。 利用三维特征形体布尔运算的重建方法，用OpenGL技术在Windows Visual C++ 6.0环境进行三维特征重建，使重建的结果易于在后续研究和实验中广泛深入地应用。 本方法是从通用的三视图中提取三维特征信息，并对二维信息进行了预处理，在实现过程中采用了OpenGL技术，因此本文所提出的方法具有普适性和实用性。更多还原

【Abstract】 When a new product is designed in the ideas and studied whether it would be developed, we hope that it can be trialed and tested such as intervene checked, property calculated, framework and kinematics and dynamics analyzed, third dimension showed. Modeling 3D virtual solid is the base of the studies, trails and tests.The engineering drawing, made up of the three views, have been a general method expressing the 3D solid completely with 2D information in engineering project. Modeling 3D solid is intricacy, so it is necessary that a conversion is set up from engineering drawings to 3D solid model.A 3D solid is made up of a series of 3D features, so the key task is how to recognize the 3D feature information from 2D drawing data.After studied the algorithms of the previous scholars, the paper brings forwards a method about 3D reconstruction of virtual solid, based on feature-recognition from the DXF drawing data of 2D orthographic views.The paper analyzes the framework about the data of DXF drawing, and gets the 2D drawing information, and sorts the drawing elements in order to recognize 3D features conveniently.The DXF data of 2D information are preprocessed, the three views are recognized automatically, and the project center is found, so the difficulties of feature reconstruction are depressed and the efficiency of the algorithmic is increased.According to the rules about orthographic projections, a method of 3D feature recognition is made, which recognizes 3Dfeatures not only by 2D drawing elements but 3D solid.With Boolean calculation of 3D feature solid, the solids are reconstructed by OpenGL technology in Windows Visual C++ 6.0. It can be used farther in studies and tests later.The method searches the information of 3D features from three-views drawing, and pre-processes the 2D data, and generates 3D solid with OpenGL, so the method of 3D reconstruction in this paper is general suitable and practicability.更多还原