citygml2-to-citygml3

A Java tool used to transform CityGML v2.0 to CityGML v3.0 files.

This project is still in early development and subject to change. (However, it is already usable/useful and many datasets from different cities and countries could be successfully transformed.)

How to run

1. The source code can be cloned using

   git clone https://github.com/tum-gis/citygml2-to-citygml3

   or downloading the latest release here.

2. The program can then be executed by running the Run.bat file (in Windows) or using the following command line:

   java -jar citygml2-to-citygml3.jar

3. The result is by default saved in folder output, such as output/FZKHaus_v3.gml (only visible after the program is complete). Simply open this folder/file to see the output.

Configurations

The program settings can be adjusted in the configuration file SETTINGS.txt. Depending on the use-case, users may change these configurations to fit their needs:

Parameter	Description	Default
INPUT_FILE	The location of the source CityGML v2.0 file	input/FZKHaus.gml
XSL_FILE	The location of the XSL file used for transformation	xsl/Transform.xsl
OUTPUT_FILE	The location of the transformed CityGML v3.0 file	output/FZKHaus_v3.gml
LOD4_TO_LOD3	Set to true if all found LOD 4 elements are to be replaced by the corresponding LOD 3 elements. The value false will remove all found LOD 4 elements.	true
LOD4_GEOMETRY	Specifies how to handle found lod4Geometry objects. If the LOD4_TO_LOD3 is set to true, lod4Geometry can either be converted to lod3MultiSurface, lod3MultiCurve orlod3Solid.	lod3MultiSurface

For reference, the file FZKHaus_v3.gml, which contains all LOD 0-4 information, can be used as an example of how the transformed file should look like.

Namespaces

To produce the best results, the input CityGML document must satisfy the following conditions:

1. It must be encoded in CityGML v2.0;

2. All namespaces and schemata must be declared in the root element (i.e. CityModel) and nowhere else (e.g. local namespaces in elements other than the root are not recommended);

3. Namespace prefixes and URIs as well as schema locations must correspond to the values allowed by the tool.

Please ensure to check the namespaces and schemata of your CityGML documents accordingly before executing the tool.

The list of allowed namespaces in CityGML v2.0 as well as in v3.0 are selected by default as follows:

Namespace prefix	Module	Namespace URI in CityGML v2.0	Namespace URI in CityGML v3.0
xmlns:app	Appearance	http://www.opengis.net/citygml/appearance/2.0	http://www.opengis.net/citygml/appearance/3.0
xmlns:brid	Bridge	http://www.opengis.net/citygml/bridge/2.0	http://www.opengis.net/citygml/bridge/3.0
xmlns:bldg	Building	http://www.opengis.net/citygml/building/2.0	http://www.opengis.net/citygml/building/3.0
xmlns:frn	City Furniture	http://www.opengis.net/citygml/cityfurniture/2.0	http://www.opengis.net/citygml/cityfurniture/3.0
xmlns:grp	City Object Group	http://www.opengis.net/citygml/cityobjectgroup/2.0	http://www.opengis.net/citygml/cityobjectgroup/3.0
xmlns:con	Construction		http://www.opengis.net/citygml/construction/3.0
xmlns:core	Core	http://www.opengis.net/citygml/2.0	http://www.opengis.net/citygml/3.0
xmlns:dyn	Dynamizer		http://www.opengis.net/citygml/dynamizer/3.0
xmlns:gen	Generics	http://www.opengis.net/citygml/generics/2.0	http://www.opengis.net/citygml/generics/3.0
xmlns:luse	LandUse	http://www.opengis.net/citygml/landuse/2.0	http://www.opengis.net/citygml/landuse/3.0
xmlns:dem	Relief	http://www.opengis.net/citygml/relief/2.0	http://www.opengis.net/citygml/relief/3.0
xmlns:pcl	PointCloud		http://www.opengis.net/citygml/pointcloud/3.0
xmlns:tran	Transportation	http://www.opengis.net/citygml/transportation/2.0	http://www.opengis.net/citygml/transportation/3.0
xmlns:tun	Tunnel	http://www.opengis.net/citygml/tunnel/2.0	http://www.opengis.net/citygml/tunnel/3.0
xmlns:veg	Vegetation	http://www.opengis.net/citygml/vegetation/2.0	http://www.opengis.net/citygml/vegetation/3.0
xmlns:vers	Versioning		http://www.opengis.net/citygml/versioning/3.0
xmlns:wtr	WaterBody	http://www.opengis.net/citygml/waterbody/2.0	http://www.opengis.net/citygml/waterbody/3.0
xmlns:tsml	TimeseriesML		http://www.opengis.net/tsml/1.0
xmlns:sos	Sensor Observation Service	http://www.opengis.net/sos/2.0	http://www.opengis.net/sos/2.0
xmlns:xAL	eXtensible Address Language	urn:oasis:names:tc:ciq:xsdschema:xAL:2.0	urn:oasis:names:tc:ciq:xsdschema:xAL:2.0
xmlns:xlink	XLink	http://www.w3.org/1999/xlink	http://www.w3.org/1999/xlink
xmlns:xsi	XML Schema Instance	http://www.w3.org/2001/XMLSchema-instance	http://www.w3.org/2001/XMLSchema-instance
xmlns:gml	Geography Markup Language	http://www.opengis.net/gml	http://www.opengis.net/gml/3.2
xmlns	Default namespace	http://www.opengis.net/citygml/2.0	http://www.opengis.net/citygml/3.0

The bold namespaces listed in the table above are new in CityGMl v3.0 compared to v2.0.

Note that the XML schemata for CityGML 3.0 are still in active development and subject to change. For the latest XSD files, please refer to the OGC CityGML 3.0 Encodings GitHub page.

Supported CityGML feature types and elements

The list of supported CityGML v3.0 feature types and elements in the current implementation is shown as follows (note that this list may change in the future):

• gml:name
• creationDate and other similar date/time elements
• externalReference
• core:appearance (both app:ParameterizedTexture and app:X3DMaterial)
• genericAttribute (gen:StringAttribute, gen:intAttribute, gen:doubleAttribute, gen:dateAttribute, gen:uriAttribute and gen:measureAttribute)
• bldg:function
• bldg:roofType
• bldg:heightAboveGround
• BoundarySurfaces and BuildingParts
• AbstractConstructiveElement such as Window and Door (as VoidSurface)
• AbstractConstructionSurface such as GroundSurface, RoofSurface, CeilingSurface, OuterCeilingSurface
• BuildingFurnitures
• BuildingInstallations
• And many more...

For the list of changes please refer to the change logs.

Below are the visualization screenshots taken in FME of the transformed sample dataset FZKHaus_v3.gml in 3D and 2D respectively:

Other Notes

Currently, only the Building module is supported.

The implementation was tested on a limited number of samples provide in CityGML 3.0 and thus that may not solve all use cases.