An Approach On The Adaptive Rotation Of 3D Landmark Symbols In Mobile Map

When the expression of information in the map has the similar vision to the real world,the surroundings can be more easily identified.In existing mobile 3D maps,as the mobile user moves,the orientation of 3D symbol won't transform angle accordingly while user location changes,producing differences between the 3D symbols orientation presented on map and the orientation of buildings based on individual perspective in real circumstance,which increases the time of users' mental rotation.In the mobile computing environment which operational ability is poor and data storage capacity is low,true 3D modeling of landmarks can effectively reduce the amount of other general model data,and improve the efficiency of 3D map display.Above all,this paper has a study on 3D landmark symbol adaptive rotation method which can meet the users' observation in real world based on the individual perspective.That is according to the relative position of user and 3d landmarks,take 3D landmark symbols within the mobile device screen to rotate adaptively,in order to realize the orientation of landmark buildings as same as in the real world while the user with third-person perspective viewing the map and reduce the user's mental rotation process.This paper studies in detail,the main research contents and achievements as follows:1.Theoretical research on the orientation expression of 3D landmark symbol based on individual perspective.Summarizing the basic expression factors of individual perspective on the map,and analyze the relationship between individual perspective,mental rotation and orientation of 3D landmark symbol.Thus put forward the theoretical research on the orientation expression of 3D landmark symbol based on individual perspective,which provide theoretical basis for 3D landmark symbol adaptive rotation method.2.A study on 3D landmark symbol adaptive rotation method.Determining the adaptive rotation parameter threshold of 3D landmark symbol and rotation angle based on the theory of individual perspective and referencing computer graphics transformation method as well as computer visual perception theory,and realizes the method of 3D landmark symbol adaptive rotation.This study can be extended to the adaptive rotation of landmark and even to varied elements on mobile device.3.The verification and applicability analysis experiment about the adaptive rotation method of 3D landmark symbol.Take the realistic environment which is around the Xin jiekou subway station in the city of Nanjing as the experimental area and take the landmarks to be true three-dimensional modeling.Select the suitable experimental methods to take the verification and applicability analysis experiment about the adaptive rotation method of 3D landmark symbol in this study.The feasibility experiment shows that the method could effectively realize 3D landmark symbol rotate as the user moves.At the same time,the experiment of adaptability analysis shows that the design of 3D landmark symbol based on the individual perspective basically meeting the user's visual perception level and cognitive psychology,and the way has higher satisfaction.The method of adaptive rotation could improve the correct rate of recognition about landmark symbol to reduce the navigation time.This method is only applicable to regional which the landmark Intensive value is small.