Research Of Real-Time Visualization Of Engineering Construction Management Based On GIS

The construction of the huge hydroelectric engineering is a complex and hard work. Using computer to aid management is the objective which people have being pursuit for. With the technique of Geographic Information System applied in the hydroelectric engineering construction, the theory and the methodology of the computer visualization and its application are deeply studied in this thesis. Based on the digitalization, intuition and visualization of the information, the complex processes of the engineering construction are visually expressed, which provides an effective tool to roundly, truly and fleetly analyze and comprehend the whole engineering construction, and achieve the effective application and the scientific management of the engineering construction information. The study would be very helpful to promote the reformation of the hydropower engineering construction with the tendency to the digitalization, visualization and intelligence, and the perspective of its application would be very bright. Summarily, the main studies and achievements of this thesis are listed as following: Firstly, the theory and methodology of GIS-based construction management of the hydropower engineering is studied in this thesis in order to enhance the level of computer-aided management, simplify the complex design processes and improve the design efficiency. Based on the method, the design modeling and the interactive control could be realized conveniently and visually during the design processes, and the visual representation of design results could be obtained. To the end, the efficiency and quality of the engineering construction could be largely promoted. Secondly, the system framework of the GIS-based three-dimension real-time visualization simulation applied to hydropower engineering construction is designed in the thesis. At present, there are two main integrating ways on GIS and the visual simulation, which are:(1) Melting pot, which data transmission is convenient, effective and simple, but needs expensive expense and longer development cycle. (2) Expansion schema, which is realized to data exchange and information share by establishing expansion zones, and this schema is easily developed, and needs cheap expense, and conveniently maintained, further researched. To realistically and vividly describe the space-time logistic relations of the complex hydroelectric engineering construction, and simplify the simulation models and get the information directly, the mixed way of both is presented and applied in this thesis. Thirdly, in order to solve the visualization problem of the terrain, the rendering algorithm of real-time continuous level of detail of the terrain is presented based on the object-oriented, view-dependent and DEM. And the multi-resolution model of level of detail is constructed by use of crossed quad-tree structure, which is based on the GRID DEM and the right-angled triangle cell. Under the permission of visual effect, and real-time rendering efficiency of the algorithm of the virtual terrain considered, four criterion principles in relation to the view-dependent based on the traditional SOAR grid algorithm are studied, which include as follows: (1) Screen space error. (2) Elimination of the sightless vertex. (3) Judgement of the vertex direction. (4) Coefficient of the angle of view volume. Fourthly, in order to implement the rendering algorithm of the terrain, a system structure of the virtual terrain including three ties based on the object-oriented technique is presented in this thesis. The whole terrain simulation processes are divided as the preprocessing, the real-time processing and the post processing. During the preprocessing, the structure file *.ecsiinfo that will be provided for the real-time process is produced after analysis of the DEM; Constructing and rendering of the real-time grid are finished on the basis of the optimal algorithm and the four criterion principles during the real-time processing; The exporting of image, the movie recording of the 3-D visual rambling and the querying of the 3-D information are disposed in the post processing. As a result, the real-time 3D visual terrain system based on the techque of DEM and LoD has been developed. Fifthly, the extending technique of terrain visualization based on fractal theory is presented in this thesis. According to the excavating and filling of the terrain of the engineering construction, the rendering algorithm of the terrain that combines real terrain data and fractal theory is disposed, which can not only render the whole terrain shape with the real terrain data, but build the detail part of the terrain by fractal theory. The algorithm is superior to the other two algorithms, which overcomes the storage problem of the scale terrain data and assures more reality of the terrain. Sixthly, the framework of the visual simulation is designed to 3-D DAM filling based on GIS. The system make fully use of object-oriented modeling, MVC software mode, GIS component, spatial database, big file memory mapping, SOCKET communication technique etc, these techniques can not only simply modeling and describe the complex progresses of the DAM construction, but also analysis and compare different schemesvisually, thus it can provide scientific decision-making theory for the planning, the schedule controlling, and the management of the DAM construction. Based on the above theory, a 3-D simulation system of the DAM construction has been developed. At last, a detailed conclusion on the whole work and the research results on this paper is summarized, and the improved aspects and the proposals to the future are discussed.