Industry development and research status based on 3D GIS technology

One 、 The three dimensional GIS The status quo of the research on

        Along with the rich and colorful clothing, food, housing and transportation , The three dimensional GIS Technology is increasingly used in various fields , Such as mining 、 Geology 、 Crude oil and other manufacturing industries . The three dimensional GIS The division of research and analysis responsibilities is becoming more and more detailed , Several research contents have been developed .

1、 The three dimensional GIS Research and analysis of data model

        Because there is no physical model or abstract performance to express all levels of the physical object , It is often impossible to conceive a general data model suitable for all situations , Especially in solving such complicated situation as three-dimensional physical geography indoor space , Some models , Such as CSG,BR It helps to describe the objectives of the code ; And some models , Such as TIN and TEN It is helpful to describe the overall goal of irregularity . Choosing a single data model can not carry out a reasonable description of various types of indoor space objects , And three-dimensional GIS Its main use is very common , The actual operation and analysis of the overall goal of indoor space for different purposes are different , Such as big cities and mining , The former one will carry out landscape analysis , The latter one is to carry out coal roadway network analysis . 

2、 The three dimensional GIS The growth of software

        High tech is growing , The three dimensional GIS The software industry is growing rapidly .
         First ,GoogleEarth A lot of satellite images in the form of three-dimensional earth 、 High definition aerial photos and Simulation of three-dimensional image mechanism together , Enable customers to access the earth from a different perspective .

         second ,WorldWind yes NASA Published an open source natural geography spectrum software , from NASAResearch Development design ,NASALearningTechnologies To grow , It is a data visualization globe , take NASA、USGS And others WMS The image presented by the service provider relies on a three-dimensional earth model , It also includes the presentation of Mars and the moon .

         Third ,SkylineGlobe Commodities can rely on satellite images of soil layers 、 The airline image creates a high pixel 3D Virtual Earth scene .Skyline Strong spatial data display function , Applicable interactive mapping tools , Show 3D precise measurement and geomorphic analysis tools , Show that the database port is applicable to Oracle,ArcSDE, Strong ability to solve data problems .

         Fourth 、VirtualEarth 3、 ... and d can Show detailed interactive 3D photos , It is a searcher based on topographic map , Set high-definition aerial photos 、 Topographic map 、 Enterprise yellow page data in one .

         The fifth 、ArcGISExplorer Is a completely free virtual earth computer browser , Show me at will 、 Quickly 2D and 3D Geographic information access , Filled with challenges and concise and practical .

         The sixth 、 Chinese software EV-Globe, It has a wide range of 、 a large number of 、 Multi source data integrated management method and rapid 3D real-time data roaming function , Applicable to 3D indoor space search 、 Analysis and operation , Can be compared with basic GIS Software integration , It can easily and quickly build a 3D spatial data service system , It can also rapidly expand to three dimensions .

         The seventh 、GeoGlobe It took experts and professors like lideren and gongjianya of Wuhan University nearly ten years to create , A large number of seamless splicing indoor spatial data institutions around the world under the cyberspace developed by the State Key Laboratory of surveying, mapping and remote sensing information engineering of Wuhan University 、 Management method and data visualization software .

        These software are all three-dimensional GIS Is a very classic software , In which the ,Skyline Famous for large-scale scenes , Growing very fast , This kind of software is the most suitable for in-depth analysis, learning and training .

Two 、 The three dimensional GIS Core technologies

         The three dimensional GIS The main performance must be carried out in the three-dimensional natural environment , 3、 ... and d Situational 3D Rendering is indispensable dAPI. There are three popular at this stage dAPI Yes SiliconGraphicsInc.(SGI) Enterprise OpenGL、 Microsoft's DirectX And its Hedi、Glide、Java3D and VRML etc. . In this thesis , Rely on three-dimensional 3D 3D marking of rendering technology 3D Rendering is also one of the difficult problems in research and analysis .

1、 Depending on OpenGL and DirectX The 3 d GIS

        OpenGL Hyperevolution comes from SGI Early stage of 3D port IRISGL.IRISGL One limitation of is ： It only browses the features presented by the lowest hardware configuration .OpenGL Is an open specification , Very good colonization characteristics , It works Linux and FreeBSD Of PC Next , You can even apply graphics card acceleration .

        DirectX,（DirecteXtension, Generic term DX） It is a multimedia system programming port established by Microsoft . from C++ Computer language retention , Comply with COM. The latest version is DirectX11, Built on a new Windows7 On . In which the Direct3D And DirectDraw Integrated into DirectXGraphics.

2、 Depending on Java3D and VRML The 3 d GIS

        Java3DAPI yes Sun Defined to maintain three d Port to display information . 3、 ... and d Technology is the bottom layer of display information technology ,Java3D Show the support of Java Top level port of .Java3D hold OpenGL and DirectX This lowest level technology is packaged in Java Port . The idea of this kind of new upgrade makes three d Technology is becoming less complex and able to Add to J2SE、J2EE A complete set of structures .

        VRML Is a commitment to WWW（ The Internet ） And the three-dimensional image marking language . The full name is virtual reality technology modeling language , By VRML The association conceived .VRML The specification defines the coding format for describing the three-dimensional model , It also defines the number and behavior pattern of narrative interaction or scripting .

3、 Depending on Heidi and Glide The 3 d GIS

        Heidi It is a pure broken instant mode port , Key application development . The famous three d The program flow software is shown in Figure 3 dSTIDIOMAX/VIZ、AuotCAD、 Economic development model 、 Business service pattern demonstration and mechanical design are applied Heidi Systems software . And DirectX and OpenGL contrast ,Heidi Just an initial target port , Single function request , With the help of the application specification page or immediately use the special three d Integrate ic To develop graphics card acceleration .

        Glide yes 3Dfx Interactive graphics released by the company SDK Part of , Its key purpose is to help developers improve the hardware configuration of graphics , It's for 3Dfx The company developed and designed Voodoo Series of products are designed based on graphic accelerator card .