Research On Large-scale City's 3D Scene Rendering Technology

Construction of smart city is an effective way to achieve the sustainable development and enhance the comprehensive competitiveness of cities.Researching on 3D modeling and visualization of virtual city based on virtual reality and computer graphics technologies have practical significance to promote the construction of smart city.Based on the research of large scale 3D scene visualization and the needs of practical research projects,this paper focuses on the research of large scale 3D scene modeling and data organization,visualization technology,Then develops a smart city visualization system,which integrates massive terrain and image data,3D city model data and vector data.The main research contents and innovations are as follows:1)Study and improved the Chunked LOD algorithm,based on BVH index to construct the scenario tree.Appling the screen space error(SSE)algorithm as the scene node segments based on real-time scheduling,global terrain and massive tilt photography city 3D model of scene.Experimental results show that the algorithm can find a balance between visual effects and rendering efficiency,and meet the requirements of real-time rendering of 3D scenes.2)Aiming at the rendering problem of massive urban buildings,a method based on graphical image fusion proposed.The algorithm adopts a vision classification rendering strategy.Firstly,the view frustum segmented in parallel,and then the graph and image combination method used to achieve more massive urban architectural model scene rendering.The experimental results show that the algorithm can effectively improve the system's carrying capacity under the same hardware conditions,and achieve more massive building scene roaming,and achieve the complete rendering of the scene without loss of vision.Combined with Chunked LOD algorithm,the integration of terrain and tilt photography 3D model and massive building solid model data realized.3)According to the actual needs of the application,studied the index and organization method of multi-source heterogeneous City geospatial data,design the global terrain image,3D model and entity model building massive city photography and other kinds of tilt data integration of city spatial data engine architecture.4)Integrates the theoretical research results of this paper,this system have been applied in a number of research and engineering projects.Design and developed a prototype system based on the mobile platform.