Real Time Simulation Of The Building Shadow Based On HTML5

With the release of HTML5, Web GIS has a new opportunities of development, which can discard the Flex Silverlight plugin, etc. HTML5 provides many API without plug-ins which can make the Web GIS has a strong interactive ability, good user experience and many other advantages. But the limitation of the two-dimensional Web GIS plane map forms can not meet people’s daily life, then the three-dimensional Web GIS has become mainstream in the field of geographic information system, but the present stage development of 3D Web GIS rely on the cost and speed effects, which limit the 3D Web GIS application. In this paper, in Arc GIS Server platform using HTML5 technology rendering 3D buildings shade model in the Canvas, which simplify the difficulty of the 3D Web GIS visualization. In addition to the succession of the twodimensional Web GIS plane map in data acquisition, processing and analysis of the powerful, intuitive and the real space performance ability, and making up for the limitations of the twodimensional Web GIS graphics the performance of city construction.It has an important significance to the shade analysis from C/S to B/S.With the development of Web GIS technology and the study of three-dimensional sunshine analysis model, the traditional CAD sunshine analysis model has been difficult to meet the city planning on the image, accurate, fast requirement. Therefore, this paper proposes to establish the real-time simulation architecture shadows system based on HTML5, and the system can calculate the building at any time of the solar declination angle, solar azimuth and solar elevation, the day of sunshine time and annual sunshine time. Three dimensional structures shadow length calculation can help designers to provide fast sunlight analysis based on the data, and to provide auxiliary decision support for the urban planning department.This paper introduces the parameter of the building shadow length and sunshine time, and analyzes the calculation method of building shadow length and sunshine time based on Web GIS. And the 3D building model is designed, and the real-time simulation system HTML5 shadow of buildings based on the overall design and function module design, two-dimensional data embedding and operation, sunlight analysis, key technology of 3D data model implementation are described in detail the key technology involved. Finally, this paper takes Xicheng District of Beijing City as the experimental object, the development of real-time simulation system based on HTML5 architecture shadows, realize the 3D building model, calculating sunlight render and display the shadow length and sunshine time calculation and other functions, for the establishment of three-dimensional City sunshine analysis provided a good reference.