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오는 11월 22일부터 24일까지 네델란드 암스테르담에서 개최되는 GeoBIM/GeoDesign 컨퍼런스 발표자로 선정되었습니다. 이 대회에서 mago3D에 대해 발표할 예정입니다. 





제출한 초록은 다음과 같습니다. 


Title: Introduction of Mago3D, a Web Based BIM-GIS Integration Platform on Top of Open Source GIS


This presentation is about web based BIM-GIS integration platform called Mago3D which utilizes and expands many of existing open source GIS such as Cesium, NASA World Wind. 


Although there have been numerous attempts to integrate BIM and 3D GIS on a single geospatial platform, the outcome of those attempts are not so satisfactory till to date. Difference of data model, massive number of objects to be rendered, big volume of file size are among those major technical barriers that hindered seamless integration of BIM and 3D GIS. And there are many increasing demands to integrate BIM and 3D GIS on a web browser since web environment has been proven as an effective collaborative platform in architecture and geospatial areas.


This talk introduces an open source based BIM-GIS integration platform called Mago3D(https://github.com/Gaia3D/mago3djs) that could manage, handle, and visualize massive 3D data from BIM/AEC and 3D GIS simultaneously on a web browser. 


Mago3D platform has been developed on top of well-known open source GIS projects – e.g. Cesium(http://cesiumjs.org/) and NASA World Wind(https://worldwind.arc.nasa.gov/) - to make the best of their existing features and at the same time to expand the functionalities to BIM and AEC(Architecture, Engineering and Construction) areas. 


Mago3D has been designed and implemented as a JavaScript plug-in for existing WebGL Globe – e.g. Cesium, NASA World Wind - to expand WebGL Globe's functionality and usability to indoor space and architectural(BIM) areas. To do this, Mago3D.js has been designed and developed as a WebGL independent JavaScript to avoid lock-in to specific WebGL Globe while keeping the portability and expandability of Mago3D.js intact. 


Mago3D.js is composed of 6 main components like follows: 1. Mago3D Connector that interacts with WebGL Globe such as Cesium, World Wind. 2. Mago3D Renderer that shades and renders 3D data. 3. Mago3D Accelerator that carries out performance enhancing such as frustum & occlusion culling, indexing, LOD(Level Of Detail) handing. 4. Mago3D Data Container that contains and manages 3D data. 5. Mago3D Process Manager that manages whole process from data receiving to rendering. 6. Mago3D REST API that provides API for 3D data sending and receiving.


By plug in Mago3D.js to Cesium, NASA World Wind, or other WebGL Globe, users can expand those WebGL Globe functionalities and usability to BIM and indoor space without losing the features provided by WebGL Globe as default functions. 


One of big hurdle to integrate BIM and 3D GIS simultaneously is handling and visualization of massive 3D data. The file size of 3D surface model converted from parametric BIM model is usually very large. And converted 3D surface model has a tendency to contain many duplicated objects and meshes since those objects are mainly artificial ones. It is usually big challenge to visualize those large size 3D surface model with WebGL Globe itself without applying special techniques to handle it. 


To overcome this hurdle, new format called F4D has been developed for reducing file size and increasing rendering speed. F4D can be regarded as a service format for increasing 3D data service speed over the internet just like tile map service in 2D GIS does the same thing. F4D format aims at reducing file size of surface model by removing duplicated objects and recording only one object information for duplicated objects with block reference model. F4D format can contain unique mesh IDs, transformation matrix, and color to constitute each 3D objects also. 


F4D format is not file based but folder based one that contains several datasets in folders. F4D format is composed of 1 header file and 3 sub folders, those are HeaderAsimetric.hed, Bricks folder, Models folder and References folder respectively. Parents folder name of datasets is the same as that of object name in BIM or other 3D files. 


To increase the rendering speed and to reduce network traffic, F4D adopted variable depth octree indexing. This indexing recursively decomposes the 3 dimensional space and removes empty space till to find so-called ‘Survived’ octree. This kind of Octree indexing gives several benefits over conventional method. First, server can use this indexing information as an efficient data packet. Second, client can increase the rendering speed by easily determining which object should be drawn. Thirdly, network traffic can be reduced by sending/receiving the bundle of Octree data.


Also a format converter that converts popular 3D format to F4D has been developed. Currently industry standard IFC(Industry Foundation Classes), JT(Jupiter Tessellation), and popular 3D formats such as OBJ, 3DS, COLLADA DAE can be converted to F4D format. F4D format coupled with Mago3D.js has proven that it can increase memory management efficiency and rendering speed. MAGO3D can visualize massive 3D data including indoor objects, at least 100k objects, in a single scene seamlessly with traditional outdoor 3D GIS objects on a web browser. Although Mago3D is a quite brand new platform in BIM-GIS integration business area, it has attracted much interest from the related industry in Korea. 


2017년 8월 4일

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