The Plug-in Interface Research And Realization Of Geospatial Feature Rendering

The geospatial feature rendering is the process that uses symbol, annotation andcolor to express geospatial feature, in order to better express the content of map, andmake it easier to understand the content and use of the map for the readers.At home and abroad, the mainstream GIS software platform, such as foreignArcGIS software and domestic MapGIS software, each offers a complete mechanismon the realization of geospatial feature rendering, also meets application on somedegree. However, with the development of GIS mapping technology, some newrequirements are put forward on the geospatial feature rendering, such as in the samelayer, the features with same properties need to be divided into a subclass, and then berendered based on the subclass; or they can be divided into subclasses either byattribute fields or by graphics; and the render information is saved with the geospatialfeatures in the same file and so on. All these problems cannot be solved by themainstream GIS software at the moment.In view of the above problems, this paper presents a realization mechanism ofobject-oriented geospatial feature rendering, and will be studied from the followingseveral aspects:(1) Study on the realization mechanism of geospatial feature rendering. Theobject-oriented geospatial feature rendering presented by this paper is based on the ideaof subtype in ArcGIS. First, all the features in the layer should be divided into differentsubtypes, then associate symbols, annotations and colors with every subtype, finallyexecute the rendering process.(2) Study the symbol system, note system and color system in the process ofgeospatial feature rendering. From the storage in the database to functionalapplication of the symbol system, note system and color system, study the realizationand principle, and make it more convenient to serve the geospatial feature rendering.(3) Study on the pluggable expression of the function module of geospatial featurerendering. The function module is integrated into GeoProbe platform by the way ofPlug-in, to apply the function, and test the feasibility of the plug-in, that provides thefoundation that the function module will be integrated into other GIS software platform,to solve the Sharing problem between different platforms.