从三视图重建三维形体技术的研究

本文着重就平面体与圆柱体的某些组合,设计了一种从三视图自动重建三维形体的算法。该算法在Wesley-Markowsky关于平面体的分层重建算法的基础上,进行了某些改进与补充,并吸收了Aldefeld算法中有关结构模式识别的思想。理论分析与程序运行结果表明,该算法可以排除病态解,并在多解的情况下求出全部解。与目前所见国际上有关同类问题的研究相比,对圆柱体的覆盖域有所扩展。     

三维几何造型系统—GEMS

GEMS是在32位微型计算机图形系统或CAD工作站上运行的、用长方体、圆柱、圆锥、球、环、平移体、回转体、部件等十余种体素,经几何变换和集合运算,构造成实际的比较复杂物体的三维实体造型系统。它具有分层模块结构、全交互的用户接口、形象直观的输入方式、数据表格驱动的屏幕菜单、形体的层次网状定义和调用、基于结构的实体几何(CSG)和边界表示(BReps)的存储结构、正则集合运算、与PHIGS图形标准一致的输出流水线、多种实用的变换、成角剖切、体内巡视动进、贴面处理、便于移植等特点。它可直接应用于空间布置、建筑方案设计、机械零部件的CAD/CAM、结构分析等领域,也为进一步开发模拟仿真、计算机视觉、机器人等实用系统打下了良好的基础。     

Technical Summaries of GEMS

GEMS is a solid modelling system running on CAS workstation or 32 bits microcomputer with graphics terminal.Complex solid obj ects are built from transformation and set operations upon box,cylinder,cone,sphere,torus,sweeping object and other primitives.CEMS has explicit reatures.e.g.hierarchical modular structure, interactive user interfaceintuitional input,screen menu driven by data table,defining and instancing object in network construction,storage bases on CSG(Constructive Solid Geometry)and BReps(Boundary Representations).regularized set operations,transformation pipeline consistent with PHIGS graphics standard,various transformations,cutting object with two sections in arbitrary angle,patrolling to view the inside of an object,mapping patterns onto surfaces of an object etc.,Not only can it be used for the fields of spatial planning,architectural plan,CAD/CAM for machining,structure analysis,but it is also fundamental for developing the practical system of simulation,computer vision,robotics and so on.