Researching Data Generating And Extracting Method Of3D Pipe Ends Models Based On ObjectARX

Pipes are indispensable applied materials in some industries， such as constructing largeequipment, pipeline, building bridges, building houses, etc. In some fields, a lot of pipes areneeded. For building of the Bird’s Nest National Stadium in Beijing, the whole framestructure of the stadium is a series of pipes. The newly produced pipes are generally notdirectly applicable to industry. Most of them need to receive further treatments which cutthem along through line.there are also different kinds of intersecting angle existing in someof these intersecting pipes. Given this background, pipe-cutting machines have becomeessential machines in relevant industry. To achieve the standard for cutting, how to work outintersecting line of pipe joints has become one of the problems solved firstly. Main contentsin this paper are about developing a king of software which can automatically readAutoCAD3D drawing files, and obtain cutting data without any human intervention.The intersecting line is calculated by hand at first, if the type of cutting pipes does notneed extremely complicated calculating formula and its computing weight is relatively small,this kind of handwork is quite qualified. But, when there are considerable amounts ofcutting pipes or some parameters in formula are hard to calculate, the method of calculatingin manual is useless. Therefore, to avoid the handwork problem that presents a largeworkload and difficult to calculate, and obtain cutting data, a kind of automaticprogramming method is developed in this paper. By using this method, the only workneeded to do is to read the graphic files and obtain the geometric information; cutting datacan be automatically obtained. In the other hand, the generating data by automaticprogramming also prevents manual intervention from every step of programming. Takeadvantage of this, the efficiency of programming and the precision of track and angle datahave been greatly improved.After analyzing and comparison, ObjectARX which is one of secondary developmenttools based on AutoCAD and Visual C++6.0have been chosen as development tools in thissystem. AutoCAD developed by Autodesk Inc. is a cam mechanism design system; as a kindof drawing edit tools, it has become one of the most popular tools at home and abroad.Based on this background, the automatic system would have higher versatility andcompatibility, so as the worthy of development.The system with ObjectARX and Visual C++6.0as development tools fully reflects the thinking of object-oriented programming; besides of the tool of ObjectARX share memorywith AutoCAD, in the power of controlling programming and speed of executing orders part,it has much more technical advantages than any other secondary development tools. On theanalyzation of basic function request, the system is divided into several modules: generatingintersection pipe drawings, selecting pipes, traversing the line of intersecting, acquiringtrack data. Each module is been enclosed in different classes, with this doing not only forrealizing the function of all modules, but also ensuring the security during running moduleprograms. That is to say, only authorized objects can be allowed to access module forcontents, and outside objects are not authorized to make any changes to the modules. Doingit like this, effectively prevents internal data from possibly resulting damages by externalapplications, while avoid the internal programs accidentally effect each other, and improvethe robustness of the programs. The system for automatically generating the track data ofpipe intersecting lines is accomplished in this paper.