Research On Annotation Creation And Adaptive Adjustment In Plug-in 3D Scene

GIS is a spatial information system for collecting,storing,managing,analyzing,and describing data related to the spatial geographic distribution of the whole or part of the Earth's surface,originating in cartography.In recent years,GIS has gained widespread attention worldwide,with rapid developments in applied systems,systems theory,research methods,etc.With the demand for 3D GIS in navigation,geology,mining,hydrology and other fields has driven the development of 3D GIS.With the rapid development of the Internet using Internet technology to publish spatial data on the Web is an inevitable trend in the development of GIS.Map notation is one of the basic contents of the map,which helps users to quickly understand the information in the map and enhance the readability of the map.Compared to two-dimensional maps,three-dimensional scenes have richer details and a better sense of realism,but may cause users to have difficulty in perceiving the spatial elements when reading the scene,so need to add graphic symbols of text notes and other auxiliary means to enhance the readability of the scene.The automatic configuration of map notes is one of the difficulties of map mapping and GIS,the traditional automatic configuration of notes,the algorithm is too complex to meet the needs of real-time response to electronic maps,and the traditional map using static notes,can not meet the requirements of real-time dynamic display of notes in three-dimensional scenes.The problem of note placement in 3D maps faces a more complex situation than in traditional 2D maps.In a 3D map,the text of the notes is obscured by the undulations of the terrain and various 3D artificial structures.Arbitrary transformations of viewpoints in three-dimensional space can change the perspective relationship between notes and affect their relative position on the screen space,making it difficult to calculate potential conflicting relationships between notes in the pre-processing phase.Therefore,finding an efficient,high data integrity,moderate volume of data model for three-dimensional spatial data modeling,as well as the realization of spatial data publishing and maintenance on the Web and in the interactive process of real-time response to map notes to adjust and optimize the map display effect has been the focus of the GIS industry research.In order to enhance the readability of the map annotations and improve the configuration of the annotations,this study takes the semantic annotations in 3D map scenes as the object of study,and proposes a scheme for real-time dynamic adaptive adjustment of the annotations based on the line-of-sight analysis method,and evaluates the adjustment results by combining the evaluation criteria such as the correlation between the annotations and map elements.Based on this,the detection and elimination of notation conflicts,embossing,and orientation errors in notations is achieved using a combination of the 3D modeling language.The main research of this thesis is as follows.1.introduce the way semantic notations are stored in data models and related spatial properties,organize and construct 3D map scenarios.2.Build a 3D Web platform with the plug-in required for 3D modeling,publish spatial data of 3D map scene on the Web,and use JavaScript language to communicate with spatial data,and finally realize the interaction between users and 3D map scene.3.Use JavaScript language to communicate with the 3D map scene embedded in the HTML page to dynamically obtain the spatial state and spatial properties of the virtual viewpoint and the corresponding semantic notation in the 3D scene in real time,and determine the optimal solution of the notation position and orientation in the current state according to the prior analysis method,and finally feed back to the 3D scene.Finally,the experimental results are evaluated in terms of the complexity of the adjustment results,formulae and algorithms in the experimental cases.This paper provides a complete idea on the data release and visualization of 3D scenes in a network environment and the dynamic adjustment of map scene notes,which has a certain reference significance on the adaptive configuration of 3D scene hosts and expands the scientific research and application areas of 3D cartography and virtual geographic environment.Figure 27 table 3 reference 70...