Vrgis Platform Design And Implementation

Traditional geographic information system (GIS) is based on mappingand geography, and combined with computer science as an organic system.GIS system based on two-dimensional latitude and longitude coordinates andin form of map images for its output. Virtual reality geographic informationsystem (VRGIS) is a new generation of integrated and interdisciplinary systembased three-dimensional GIS data coordinate system, and its output is form of2D maps and3D VR scenes. Compared with the previous2D of GIS, VRGIScan provide enhanced data analysis capabilities, a stronger visual impact and amore realistic three-dimensional scene effects. However, due to thedevelopment of the production cost is higher than the development cost oftraditional GIS, so that developing the VRGIS platform is a means to reducethe cost of the actual project development.In this paper, VRGIS platform is designed and implemented. As VRMLand X3D is the Web VR, so the overall framework of VRGIS platform isbased on B/S architecture to facilitate the release of the scene. The VRGISplatform uses plug-in manner to extend the open source GeoServer frameworkplatform, and combined with the FreeMarker technology, the SLD technologyto complete the platform's core functions, output2D maps and3D VR scene and released via the web. Two kinds of three-dimensional data,of web3Dformat X3D and VRML,conversion method is proposed: template-based textreplacement TCM method and based on VRSLD common style conversionmethod. In order to solve the difficult of build VRML/X3D complex modeling,System designed and implemented a model library manager that responsiblefor import and export, a preview of the production, automatic classificationmanagement and model searching of external complex3D models (can bemade with the help of professional modeling tools, such as3ds max, mayaetc.), effectively improve the3D modeling capabilities of VRGIS platform.The management of platform's data is mainly through the maintenance of themodel base management and expanded the WMS data management methods.The overall framework designing of VRGIS platform is to achieve a highdegree of functional modular, ease of use and scalability. TCM and VRSLDmethods in the design have also set aside to expand the interfaces, so user caneasily add other VR output format as a platform to improve conversioncapability of TCM/VRSLD and system's three-dimensional renderingcapabilities.Finally, this paper shows three examples (including the actual chemicalplant simulation system, based on the emergency rescue of the multi-agentvirtual scene and system development demonstration system) and analyzesand compares their development process. Results prove that platform development projects only cost a relatively small number of human andmaterial resources to complete the project to generate realistic virtual realityscenes, while retaining the traditional GIS functionality and data analysis. Theplatform development can increase the code reuse rate, shorten the completionof the project cycle, and bring more economic benefits for the actual project.