Design And Implementation Of Online Interactive Visualization Tool Based On Vector Tiles

With the profound changes of the network environment and the rapid maturity of online map technology,the way of people's lifestyle and thinking have also changed.It is playing an increasingly important role in the daily life of the public due to online map does not need to install complex platform environment and is easy to use.With the popularity of online map and the perfection of its functions,the people are more dependent on the network map and put forward a more diversified demand.However,the mainstream online maps are displayed to users in a fixed style map,which cannot take into account the needs of users for personalized maps.According to the online mapping process,not only pay attention to the mapping speed,but also take into account the characteristics of visualization,this paper proposes a network map online interactive visualization user oriented method.The method is based on vector tile technology,gradually transmitted GeoJSON format data to the client side by WFS,and cached in the in browser.Users operate interactively at the browser,edit map symbols,set up vector layer styles,and determine map symbols and layer parameters.The interactive online visualization tool design based on the method,which no need to construct a huge client environment,make full use of the client in WEBGIS system CPU and GPU computing resources.It resolves the style information through scripting language,meanwhile acts on the vector data in memory.Finally,WebGL technology is used to render data into graphics and display dynamically,which reduces the dependence of data rendering on server.Experiments show that without installing any plugins in the client,this tool can ondemand loading large vector data,rich online map symbol,change the online map style dynamically.Achieve the effect of changing the form of online map expression from single expression to multiple expression.The main research content of this paper summarized as follows:(1)Research and analysis of the principle of the vector tiles generation and organization scheduling method.Combined with GeoJSON format vector tiles,the paper discusses the procedure of vector data rendering into a map in the WebGL environment.At the same time,the principle of the fusion and visualization of vector tile data in the browser end is expounded,which provides a theoretical basis for the design of online visualization tools;(2)The paper introduces the concept of self-adaption rapid mapping and analyzes the designed elements of self-adaption mapping.At the some time,the mapping relationship between input variables and output variables is discussed.Combined with the rules of cartographic knowledge and the map templates,an on-line self-adaption rapid graphing scheme design is proposed.(3)The paper explores two different methods of publishing and styles of vector tiles,and expounds the map symbol structure of different forms of points,lines,and surfaces,which serves the design and implementation of online map symbol legend generation and editing dynamically.(4)The overall architecture of online interactive visualization tools is proposed,and the relationship between the modules of the online interactive drawing tools,which includes the rendering engine module,the graph generation module,the symbol editing module and the adaptive module.At the same time,the structure and composition of each module are introduced from the perspective of system implementation.(5)Based on the theory and discussion above,a prototype online interactive visualization experiment tool is designed and implemented.The feasibility of the proposed design scheme is verified through experiments,and the effectiveness is demonstrated.This paper based on prototype experimental system uses related data to conduct experiments.Experimental results show that online interactive visualization tools based on vector tiles can adaptively load large-scale vector data,edit online map symbols,enrich online map symbols,dynamically change online map styles,real-time online mapping,while there is no need to install any plug-ins on the client side,and transform the form of online map from single expression to multiple expression.The business logic of data parsing and map rendering is placed on the client implementation,which can away from the reliance on complex GIS client configuration environment and implement map display and rapid mapping services,provide users with a feasible map mapping selection and service method.