Research On The Methods Of Automatic-generation Of 3D Virtual City

Since the Reform,the development of our country urban is rapid,The process of urbanization speed has reached double times of world same term.. How to realize the urban economy fast and sustainable development, has becomes an important issue which people closely pay attention to now. The urban informationization as a new direction for urban development, has become the "accelerator." The digitization and the informationization construction already became mainstream and tendency of the city modernization. In the urbanized process, urban planning's function appears especially important. But the traditional urban planning method is unable to adapt the urban informationization development obviously. The three dimensionalal virtual city's appearance has provided a new technology and the method for the city planning staff. The urban planning staff may work in a three dimensionalal virtual environment, to plan the city with the dynamic interactive way to carry on omni-directional carefully examining, that the traditional plan methods are unable to achieve. In this paper, proposed a research problem of the Automatic-generation methods based on the three dimensionalal virtual city.Take the new developing region in west KaiFeng as a study area,and take the urban cellular automata as the the urban development dynamics model,and take the urban planning of new region as the frame of the urban simulation development, I simulate the automatic generation and the evolutionary process of three dimensionalal virtual city.This article main research content is as follows:1.Urban function area productionFirst,under the geographic information system software's support, has completed the prepartion and handling work of the foundation topographical data, land use planning data and the developed area project land statistical data of the new developing region in west KaiFeng,which the urban cellular automata needs. Based on this, has constructed the urban cellular automaton model,and obtained the development evolution data of the new developing region in west KaiFeng from 2006 to 2020 based on the cellular automaton simulation.2. Three dimensionalal virtual ciyt model constructionUnder the three dimensionalal modelling's correlation theories and method instruction,used the three dimensionalal modelling software Terra Vista and MultiGen Creator ,has constructed the new developing region in west KaiFeng the three dimensionalal terrain and feature model,and has established the three dimensionalal model database. First,topographic maps, remote sensing image datas and roads, water systems are passed through the transformation matching,then load them into Terra Vista by the forms of DEM, remote sensing phantom and vector data,and generate the unifed terrain model of the new developing region in west KaiFeng. Second,it establishes the static building and the dynamic building models of the urban virtual landscape.The static building models are constructed by point or surface vector data stage in Terra Vista at the stage of terrain modeling.The dynamic building models are constructed by MultiGen Creator,called in the three dimensionalal scene through the three dimensionalal virtual city generating system.3. Develops the three dimensionalal virtual city generating systemFirstly in theory,it has established the three dimensionalal coordinates system and determined the three dimensionalal geometric transform, the projection transormation and viewport transformation methods. Secondly,it has developed the three-dimensional virtual city automated generation system into the VC++6.0 platform based on the GeoCA-Urban model and the OpenGVS software development kit.The system has realized multiple perspectives and the automated roaming,automated generation, dynamic display and other functions of the virtual city.The system realizes the construction of three dimensionalal virtual scene mainly through the OpenGVS software development kit.it has solved the construction of the land use unit entity data structure,the access and conversion of the land simulation data, the three dimensionalal coordinates establishment and the conversion method, the three dimensionalal urban model automatic arrangement technology,the examples of objects dynamic management techniques and the algorithms of three dimensionalal model automated succession, such as automated generation key technologies.In this paper,it uses the development evolution data of the new developing region in west KaiFeng from 2006 to 2020,and uses the system to generate the dynamic three dimensionala virtual city(2006-2020).The results showed that: This system's operating efficiency is high;The three dimensionalal visualization effect is remarkable;It can respond to the influence for the pattern of the virtual city in the different time intervals under the urban palnning;It can generate the large scale realtime automated three dimensionalal virtual scape.The research shows that adopting the high precision urban cellular automata has some definite influences upon the presicion about the generation of three dimensional virtual city.Moreover,using the small and medium scale urban function area planning to carry on the three dimensionalal urban model automatic arrangement are more reasonable,is also more real in the visualization effect aspect.