虚拟GIS下可视化建模技术研究

ABSTRACTV-GIS (Virtual Geographic Information System)is the result of combiningVirtual Reality multi-dimension GIS,a new domain of GIS.From the traditionaltwo-dimension GIS to multi-dimension GIS,GIS has been developed completely;Virtual Reality has the advantage of apperceiving and experiencing geographicdata,which makes up the deficiency of GIS.The real world is very complex,andhow to simulate the real world and reconstruct real world in computer is the base ofresearch and application;the primary problem of V-GIS is how to model thegeographic object in computer.From the real application request of V-GIS development,this paper deals withthe problem of modeling under V-GIS.The major work is as follows:1.The efficient generalization and abstraction of the real world.The objects ofthe real world are various,but the computer just can process and express a portion ofit;so we must generalize and abstract the real environment object,then define theobjects which we must model.At last the author uses Object-Oriented method togive the concept model of V-GIS Modeling.2.Research the modeling of image for the local special objects.With traditionalmodeling method of GIS we encounter some difficulties,we must keep a balancebetween the precision of model and rendering speed of computer.To make up thelack of geometric modeling the author introduces the modeling of image for thelocal special objects.3.Panoramic images are used for the estimation of landscapes,display of realestate,education etc.The author research the combination of the modeling of virtualenvironment based on panoramic images and the modeling of virtual environmentbased on geometry.4.How to use the existing data of two-dimension GIS and model thecomplicated object are the difficult problems of modeling under V-GIS to be solved.Under the need of application the author gives two solution methods separately.5.The method of Texture Mapping is used widely in the modeling of virtualenvironment.To model an important object of tree in the virtual environment,theauthor improves the modeling method which is based on Texture.6.Through the research of modeling under V-GIS,the author gives someapplications of the above research method and gets satisfying results.Key Words:Virtual Reality Geographic Information SystemVirtual-GISObject-Oriented ModelingPanoramic Imagesii