Symbolization Of3D Geospatial Models

With the development of computer hardware, software and3D visualization, more andmore map forms have appeared, and the types of the map is also becoming more and moreabundant. Among them, the3D map based on3D geospatial model can express thegeographical space by a more visual, concrete three-dimensional form, so it has been paid moreand more attention. However, the current design of the3D geospatial models are most in highsimulation stage, and its feature model can not be on behalf of the general features and can’treuse, so it hinders the system performance of the map, and there are a lot of repetitive work inthe production process, then the model data size is also too large. Traditional planar map with2D symbol system to express spatial information has greatly meet people’s geospatial cognitiondemand. Therefore, we can discuss the design of3D geospatial model from the position ofsymbol.There are two important aspects in the study of3D geospatial model symbolization: one ishow to design3D map symbol to express all aspects of the geography space informationespecially the user interested information; the two is how to organize and manage the3D mapsymbol. Firstly, the spatial cognition and3D map symbol has been studied and analyzed basedon the theory of the symbolization, then the design of3D map symbol and3D geospatial modelhas been discussed, and the effect of the symbolic model has been contrasted and analyzedthrough the examples, the design of3D map symbol base has been studied lastly. Among them,the main contents and results about the research are as follows:(1) Firstly, the progress mechanism of geospatial cognition has been studied under thetheoretical basis of spatial cognition. Then, the two transmission modes of the geospatialinformation has been analyzed and compared, and the cognitive rule of3D map spacepreliminarily has been studied.(2) Secondly, the relationship between map symbols and geographic informationvisualization has been analyzed. The definition, classification and characteristics of3D mapsymbol have been studied deeply. Then the3D map symbol visual variables have been studied, and the general principle of3D map symbol design has been summarized. All of these have laidthe theoretical foundation for the design of3D map symbol.(3) Thirdly, an expression way combining the realistic and the non-photorealistic has beenproposed based on the existing3D symbol expression. According to the respective-expressideas, the selection and classification of the symbolic target has been discussed. Then thesimplified design of3D map symbol preliminarily has been studied, and the3D geospatialmodel symbolic effect has been analyzed through the examples.(4) Finally, the3D map symbol system has been studied. Then the design of3D mapsymbol base has been analyzed, and a basic framework of3D map symbol base has been putforward.