【作者】 李阳；

【导师】 王磊；

【作者基本信息】 西安理工大学 ， 计算机应用技术， 2009， 硕士

【摘要】 本文针对三维打印快速成型系统中采用单一扫描算法效率低下的问题。借鉴几何图形相似性的原理,使用计算机中对图形建模计算相似度的方法,引出了一种基于图形相似性扫描路径检索选择算法。该算法以图形相似度为依据,对不同的图形采用各自最优的扫描算法。文章首先回顾了当前图形相似性比较的发展,着重介绍了基于几何形状特征的图形相似匹配算法。其次,根据PIC文件构造边类型数组edgtp、边属性数组edgattri、邻接边夹角数组Adj_ang存储模型表示切片图形的几何形状。并给出了基于上述模型的形式化定义,通过抽取表征edgtp、edgattri、Adj_ang的特征参数建立了一个有效的实例索引机制,提出了形状相似性及实例相似性的度量和计算方法；通过matlab仿真实验表明,采用按照图形相似性选择扫描算法的系统在正确率和效率上都优于采用单一平行扫描算法和偏置扫描算法的系统。该方法具有较好的通用性和实用性,能够有效的提高快速成型系统效率。最后,在算法的具体实现方面,采用VC++6.0编译环境,应用MFC与Matlab混合编程的方法。重点介绍了PIC文件导入与相似度计算的实现过程。通过理论分析和实验论证,认识到利用几何图形相似性思想来改进快速成型扫描算法进而提高系统的性能是可行的,文中所提的动态选择扫描算法对解决实体成型问题有一定的参考价值和实用意义。更多还原

【Abstract】 In this paper, try to resolve the inefficient problem of the RP system used in a single scan algorithm. Reference the principles of geometric similarity, use the method computer calculate the similarity of graphics modeling. Leads to a method based graph-similarity search scan path。The method is based on similarity to graphics, the different graphics use of their optimal scanning algorithm.At the first. The article reviewed the development of current situation of graphics similarity research. Focuses on the graph matching algorithm based on the geometry characteristics. Secondly, while according to the type of PIC file, create structure of edgtp, edgattri, Adj_ang graphics model that show the geometry section. And given a formal model definition of above. Establish an effective mechanism for index. Put forward methods of similarity measurement and calculation to shape similarity and Details of the similarity. Through simulation by matlab, the simulation found that the use of similarity in accordance with the graphics system scan algorithm to choose in terms of efficiency and accuracy are superior to single-scan algorithm and offset parallel scan algorithm system. It will improve the efficiency and accuracy of the Rapid prototyping system in some extent. Finally, the concrete realization of the algorithm, the use of VC++6.0 compiler environments, the application of mixed MFC and Matlab programming approach. PIC document focuses on the import and realization of the process of calculating the similarity.Through theoretical analysis and experimental demonstration, recognize the ideological similarity of the use of geometry to improve the rapid prototyping scan algorithm is feasible, as mentioned in the paper of the dynamic choice of scanning algorithm to solve the problem of forming entities have a certain reference value and practical significance.更多还原