| With the rapid development of the computer technology, Virtual Assembly Technology has been successfully applied in many fields.From the point view of the virtual reality technology, several kinds of typical virtual assembly application systems are described in this article. According to the deficiency of the existing virtual assembly system, here proposed the idea that based on characteristics unrelated to the virtual assembly. Some of the key technologies involved in the virtual assembly system are discussed in detail, and then the corresponding solutions are also gived, including the technology of the virtual hand modeling, the technology of the virtual hand interaction, the technology of the collision detection and so on. The initial development of the virtual assembly system is completed that to provide a good foundation for the future study of the virtual assembly system. The specific research work of this paper is as follows:(1) The idea is proposed that based on characteristics unrelated to the virtual assembly, that is, with unknown the part's geometry, orientation, constraints, assembly; In addition, model can also be created by different CAD systems and the virtual assembly system can also achieve its assembly, it is implemented as well as the seamless link between the CAD systems and the virtual environments.(2) The implementation of a virtual hand is completed in this paper. The geometry and motion model of the virtual hand are established by using the hierarchical modeling method in the3DS MAX and Multigen Creator software through analyzing the anatomical structure and the motion characteristics of the human hand.(3) The motion mapping that from the human hand to the virtual hand is focused on in this report. In order to operate the virtual hand in real-time, the DG5Vhand2.0is used as the virtual peripheral in this paper, the information receiver module of the data glove is developed in VC++and then the gestures information of the hand is obtained. Finally, the interaction between the human hand and the virtual hand based on the data glove is achieved through the VC++and OSG programming.(4) The collision detection between the virtual objects in the virtual scene is discussed in this text. The algorithm of the collision detection is discussed using both in the widespread area and under the OSG. The physics engine-ODE is introduced according to the complex engine model, using its own collision detection library trimesh method to achieve its collision detection combined with the OSG. It focuses on the problem of how to extract the OSG model data to construct the corresponding ODE collision geometry and how to achieve the real-time corresponding between the OSG and ODE models's lacation and status. At last, the assembly instance of the engine is realized by using above methods. |
