Design Of Symbolic 3D Map Expression Method Based On Volunteer Geographic Information Points Of Interest

With the continuous development of 3D visualization technology and the update of computer software technology and hardware equipment,as a new generation of map products,3D electronic maps have enriched the traditional electronic maps’ expression forms and data transmission modes,and can more intuitively visualize geographic spatial objects expressing people’s attention has increasingly attracted people’s attention.This research is oriented to the needs of rapid,efficient and low-cost construction of 3D maps.It is based on the selection and highlighting of important geospatial targets in 3D maps,as well as the high cost and large amount of data for modeling and expression of symbolic real 3D models.Research on the expression method of symbolic 3D maps for spontaneous geographic points of interest,designed a symbolic 3D map expression method that can highlight important objects in geographic space and has a small amount of data,and improved the multiscale expression method of scenes in existing 3D maps.Good results have been achieved.The main content of this paper includes the following aspects:1.Research on symbolic 3D maps.This article focuses on the core problem of visual representation of symbolic 3D maps based on spontaneous geographic points of interest,and proposes the concept and expression method of symbolic 3D maps.Symbolized 3D map is a way of expressing to assist and emphasize the key subject geospatial objects in the 3D map.The symbolized 3D map has the characteristics of more intuitive spatial recognition,stronger interactivity,and intelligent decision-making assistance.2.Research on construction methods of geospatial interest fields and spontaneous geographic interest points.For symbolic 3D maps,from the perspective of user space cognition and interest,based on the concept of spatial interest field,a spatial interest field based on VGI data is constructed;this method uses the interest field model to study the map users’ geographic space According to the characteristics of interest,spatial distribution and trend of interest change,then based on spontaneous geographic interest point interpolation analysis,3D symbol classification and modeling were carried out to formulate a multi-scale intelligent expression scheme of spatial data under the constraint of interest field.3.Research on symbolic 3D map representation method based on interest field model.The symbolized 3D map is based on the expression method of the symbolized 3D map based on the geospatial interest field.Combine the five LOD model ideas established in CityGML to classify the 3D map scene hierarchically,and based on the construction of the 3D map scene,the 3D map is symbolized through the viewpoint control to realize the detailed level expression of the symbolized 3D map.4.This paper studies and constructs a symbolic 3D map display system based on spontaneous geographic points of interest,including a symbolic 3D map data distribution system and a symbolic 3D map display system.The system is based on spontaneous geographic interest point data,and realizes the functions of interest point and interest area query,interest field construction,3D map viewing,GIS analysis,etc.,empirical research on the proposed theoretical methods,and discusses the practical use of symbolic 3D map The role that can be played in the application.