基于形体组合关系的基元体识别技术研究

提出了一种新的基于组合因子的基元体识别方法 .从构成复杂形体的基元体之间的组合关系类型入手 ,将组合关系分为显式组合关系和隐式组合关系 ;接着 ,针对显式组合关系在二维图纸中的投影特性 ,将其在二维视图中的相关投影定义为组合因子 ,并由此建立相应的组合关系表 ,最后基于组合关系表对具有不同组合关系的基元体进行识别 .该方法将存在于二维视图中的组合因子与其对应的三维空间中基元体之间的组合关系信息联系起来 ,具有搜索空间小、识别范围广等优点 ,并在原型系统中得到了应用

Primitive Recognition on the Base of Combined Relationships between Primitives

Primitive recognition is a key and difficult problem in 3D reconstruction. Some different techniques used in primitive recognition include bottom up approach, pattern recognition, rule based methods, etc.. To date, they are still far from the desired goal of a general solution. This paper presents a new approach to the problem. The main underlying philosophy is to view a complex part as being composed of primitives with different kinds of combined relationships among them, and to recognize these primitives by making use of the knowledge about the property of their 2D representations. Firstly, the combined relationships among the different primitives are classified into two kinds, namely, explicitly and implicitly combined relationship. Secondly, pointed to the 2D projection character of explicitly combined relationship, their corresponded projection in 2D drawing are defined as combined factor which was taken as the basis of combine relationship table. Then the primitives with different kind of combined relationships could be recognized on the base of combined relationship table. Because the technique establishes the connection between the 2D combined factors and their homologues 3D combined relationships, it can limit the search space and extend the recognition shape. Complete details are provided to illustrate primitive recognition using this approach.