{'fraction_non_alphanumeric': 0.019884309472161965, 'fraction_numerical': 0.0032537960954446853, 'mean_word_length': 4.976241900647948, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The Construction of an Open Source, Cross-Platform 3D Virtual Reality Platform to Support OGC Services of Spatial Data

This paper conducted some researches on 3D virtual reality, OGC Service and spatial data storage and management. Based on the available open-source technologies and platforms, the authors designed and implemented an integrated system to publish and display 4D products in the China western district in a 3D virtual reality platform by means of OGC map service(WMS) and coverage service(WCS). The related experiments proved that the integrated system can work very well with the data service and display and system's performance was satisfactory. This paper detailed the selection of the platforms for the integrated system and the core technology for integration and interaction. In this paper, the combination of WorldWindJava + GeoServer + OracleSpatial / SQLServer / File System were chosen. WorldWindJava is a 3D virtual reality client which can render vector data or raster data and DEM data to a 3D image by OpenGL technology. It brings a virtual reality environment to the users. GeoServer is an open source service platform, supporting for the major OGC Data Services Standards such as WMS, WCS and WFS, supporting serving both vector and raster data. The entire system implemented the data storage of two kinds of formats, files and databases. OracleSpatial are chosen as the database platform. SDO_GEOMETRY and GEORASTER components are used to store the vector and image data respectively. The core technologies to implement system integration included : WorldWind's LayerManager serve as a bridge to connect WorldWind and Geoserver. GeoServer's Oracle plug-in is used to fed data from Oracle spatial into Geoserver. The core technology of the GeoServer's Oracle plug- in utilize Oracle Call Interfaces and thin driver. By using these interfaces, users can store, publish, and explore mainstream spatial data inside the Geoserver platform. This paper conducted the experiments and tests on the data service and display of the system. In the experiments, the 4D Product data of the Western District are utilized as the data sources that include DLG in ESRI Shapefile and DOM and DEM in GeoTIFF. As we know, the proposed system is mainly composed of some open source platforms, except database systems. The experiments proved that the proposed system have a lot of advantages such as needing the shorter development cycle to build up, convenient to configure, easy to use, and easy to extend its function through the secondary development, with its data services and 3D display working very well. This integrated system put forward in the paper is a good choice for people to implementation GIS spatial data services and vivid 3D display.