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We want to use GML in our application; It is a GIS based application which simulates the real word objects (i.e. Pipes, Roads, etc) in a virtual reality environment. Currently we draw and store the geometry in AutoCAD DWGs but in future we want to change the Database. I really need to find the answers of these questions.

1- Is GML proper for encoding Geometry file (CAD,Shape,..) That contains more than 100000 features (What is the relation between data Volume and GML performance, is there any limitation?)

2- how can we check the correctness of geometry data, for example how GML Understand that 2 inner Boundaries of a polygon intersect each other, (by Schema? By special Libraries? Or it just validate GML by Schema without check the inner coordinates data)

3-If I want to use a DB, can I store GML data in XML Berkeley Database?

Thanks for your Attention

Dijkgraaf
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AliPST
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1 Answers1

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1. GML can represent both CAD/GIS data - e.g. data obtained from shape files, DWG. DGN etc. GML is used to model 3D building structures (there is a language called CityGML written in GML (see just Google CityGML). GML can represent terrain models and images (GMLJP2) also. GML is XML so the volume can be large, however, modern XML databases can easily handle databases with 100,000 features and more. GML clients (like Galdos INspector (Just Google galdosinc) can readily deal with hundreds of thousands of features (e.g. all roads in Austria) as well as with complex building models (see http://youtu.be/UR02FNfamO8).

2. You cannot validate geometry (e.g. polygon boundary intersections)just by XML schema validation, but there are special libraries and Galdos will shortly provide a GML validator like the KML validator (just Google kmlvalidator) developed for Google. This latter tool does check for geometric validity of KML.

3. GML can be stored in any database - Oracle, PostgreSQL, etc as well as XML databases. You should note that there are web services called Web Feature Service (WFS) that serve GML data.

Wh1T3h4Ck5
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rlake
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