Development Of 3D-network Electronic Map System Based On API

With the rapid development and wide application of the computer network science and geographic information system of science and technology, a new era of cartography also have sprung up with diversified development trend, based on the map on the subject of two-dimensional GIS has become a current map standard; WebGIS technology and 3 d virtual reality technology on the basis of mapping services also gradually become a mainstream development in the application of the map. However,massive amount of 3 d data stored in computer technology and network transmission technology platform for the high demand and high prices for the threshold, makes the combination of 3 d virtual reality technology and network applied in exploration is still in the experimental stage.Taking southwest university of science and technology as the experimental object,mainly for the following aspects are studied:① 3D modeling and rendering technology research3D simulation of electronic map is unique in its data portability and three-dimensional visual effect, it is need to create a 3 d model for the study area. In the research and analysis of the characteristics of different 3 d software platform, this paper chose to use SketchUp process oriented model is structured, realization of virtual campus scene reconstruction. In than rendering environment and set a model of the optimum parameters of the material, lighting, and choose the right Angle to the scene of rendering 3 d simulation model rendering.② The map projection and coordinate transformation methodMap of 3 d simulation is based on side will three-dimensional model is mapped to a projection plane projection principle, to show the 3 d visual effects for the 2.5 d map.To implement 2 d data to 3 d simulation map coordinates reproduction of one to one correspondence relation, should use mathematical relationship under the current projection map coordinate transformation formula is deduced.③ Based on JavaScript API development of WebGIS technologyRIA(RichInternet Applications, rich Internet application) technology to appear for the traditional WebGIS development mode brings new direction. The current popular RIA application framework: API technology and the REST architectural style,combining ArcGIS Server provides the convenience of the development of the interface,for this implementation has a good user experience and interactive map system provides a rich theoretical and technical support.④ApplicationsTake southwest university of science and technology as an example, and ultimately realize the query of this system, such as navigation, analysis map operation function.Summed up a set of 3 d simulation network electronic map and reasonable production and development method, looking to the future 3 d simulation, the development trend of electronic maps provide certain reference value for the future research work.