| The technology of geometry modeling and model optimizing, the real-time simulation of rainfall and snowfall in scene simulation are studied in this dissertation based on the former research "The application of virtual reality technology in the container crane training simulator". Scene system of overhead traveling crane simulator is implemented. And the real-time simulation of rainfall and snowfall in scene simulation, and the test of simulating training are realized in container crane training simulator.Firstly, according to the structure of actual overhead traveling crane, its model and the workshop are built with 3DS Max application software based on analysis of the prevalent 3D modeling methods. Meanwhile, they are predigested with the techniques of reducing the number of segments, texture mapping, Optimize Modifier. The software named WUModeler is applied to optimize the models and revise the center of gravity of the models. Consequently, the number of triangle and polygon is greatly decreased to decrease the computing amount and to increase the responding speed of the rendering, And then, the hiberarchy of models is designed in the scene, and the scene driving is achieved by loading the optimized models, setting light, initializing the viewpoint, establishing paths for the models.Secondly, particle system is applied to realize the rendering of the falling rain and snow based on analysis of traditional simulation methods in domestic and oversea. There is a big conflict between the large calculation loads of particle system with real-time require. The dissertation studies implementing the simulation of rainfall and snowfall in container crane simulator; the calculation load of system without any special weather is heavily. In order to reduce system overheads, the particles producing algorithm and the particle extents of particle system mathematics model are properly predigested and optimized. The simulation of falling rain and snow is realized in the virtual scene of container crane simulator. Otherwise, diverse scenes of falling rain and snow can be achieved by setting the parameters of the size of particle, the direction of wind and the speed of wind etc.Thirdly, according to the real commands of the driver of the container crane, the test of simulating training of container crane training simulator is realized. Meanwhile, the assistant orientation system is designed to orientate the hook quickly and exactly. Consequently, the time of training is shortened. Finally, supported by the developing platform of VC++ and WTK, the scene driving of scene system of overhead traveling crane simulator, the specific rainfall and snowfall of scene system and the testing of students operation of container crane simulator are implemented. |
