Developing And Researching The Virtual-Experimental System On Engineering Graphics Based On Virtual Reality Technology

In the teaching of engineering graphics, the part of the experiment is very important. Many colleges study the virtual engineering graphics experiment following the development of the virtual reality technology. Developing the software for the engineering graphics used modern equipments and the virtual reality technology redounds to the method and the measure in the experiment. It changes the traditional and behindhand experiment method and measure, offers experimenters the software with immersion and alternation. With this, we not only can complete some graphics experiment which can not work in traditional experiments but also can set up other innovation experiments.This paper laies out the virtual experiment on engineering graphics and introduces the method of the experiment programming. There are four modules in the virtual engineering graphics experiment based on the content and the intention: the experiment on the plane cutting solid models, the experiment on transfixion with both solid models, the experiment on constructing and designing combinatorial models, the experiment on assembling or tearing down the virtual component. The experiment on constructing and designing combinatorial models includes three experiments, the experiment on constructing and designing combinatorial models which is requested,the experiment on constructing and designing combinatorial models through reading the views and the experiment on constructing and designing combinatorial models with imagination and liberty. The experiment on assembling or tearing down the virtual component includes two experiments, the experiment on validating the assembly order and the experiment on validating the disassembly order. We build the solid model using two methods based on the characteristic of the model in experiment, including the method of modeling based on computer graphics and the method of modeling based on three-dimensional modeling software.The virtual experiment on engineering graphics is based on VRML and Java. The interactive operation is realized on communication technology between VRML and Java. This paper describes the core arithmetic and program implement in the process of designing the software. It includes the arithmetic and program implement in cutting the solid models, the arithmetic and program implement in showing the view of the solid models after cutting, the arithmetic and program implement in collision measure in the experiment on constructing and designing combinatorial models, the arithmetic and program implement in collision detection in the experiment on assembling or tearing down the virtual component.This virtual experiment system has many characteristics: 1.It is based on network. It only needs one computer which joins in network as the server. The experimenters can do the experiment through network. 2. It is flexible. The experimenters can control the virtual model freely according to the aim and the demand in the experiment. 3. The operation is alternating. The virtual model will be changed and showed in real time following the operation of the experimenter.4.The view of the virtual model is changed in real time. The experimenter will see the new view in the same web page while the model is changed in the experiment on cutting.The innovations in this paper include: 1.It lies out and designs the whole contents of the virtual experiment on engineering graphics. 2. It selects the typical models for the virtual experiment according to the contents and builds them. 3. It realizes the software based on VRML and Java. All the windows including the window for virtual models and the windows for interactive operation are shown in the same web page. 4. It builds the model in the experiment on cutting and compounding used the compuer graphics technology, realizes the flexible control. 5. It analyzes some arithmetic for realizing the software.The virtual experiment on engineering graphics will maturate with the development of the virtual reality technology and be indispensable in engineering graphics teaching. This paper studies and implements the software for virtual experiment on engineering graphics. It is significant for filling up the blank of the virtual experiment on engineering graphics, improving teaching quality and experiment level.