The Research Of Organization And Storage Methods About3D City Models

With the increase of information access means, the data size growth rapidly,three dimensional city models as the important content of3D GIS,it has greatsignificance in the construction process of digital city and smart city, but due to thecomplexity of data structure, its data size is huge. Therefore, how to efficientlyorganize and store huge amounts of three-dimensional city model data, in order tomeet the long-term management of data and3D GIS system of rapid visualization andspatial aided decision-making, become a research hotspot in recent years.For a wide range of3D city scene, the space division and the simplified model isan essential technology,the regional of formerly data partition method changesfrequently, the data update and management is difficult, so it need to find a morestable and recognition data partitioning method. In this paper, based on the previousstudies, the data partition method and model simplification algorithm is studied, andput forward the large scale map partition method based on the topology relation modeland the improved edge collapse simplification algorithm, and using the NOSQLdatabase to store authentication. The main achievement is as follows:1) The topographic map is a worldwide recognized method, with large scalestandard sheet as the modeling unit of the spatial data partition; use the spatialtopology relation model to solve the segmentation phenomenon of3D model acrossthe map, and the3D models is named after division by the unified coding rules.2) Based on the division method above, to rule-based modeling of batch, and setup four LOD classifications. Use the edge collapse simplification algorithm toextractthe correction coefficient, and modify the positions of new fold vertexin order tomake the simplified model is more tend to the original surface3) The NOSQL database has a strong advantage for mass data storage and highconcurrent access.in this paper, by constructing MongoDB shard cluster servers tostorage3D models,this storage method can be flexibly increased the shard serverbased on the amount of data, it is convenient to extensions and update the database,and verification the effectivenessthrough experiment.