OGC CityGML Writer Parameters

Specifies the version of CityGML to be written. The output documents will be quite different as CityGML changed significantly (especially with regards to the namespaces in which objects are located) between these two versions.

• Yes – This parameter writes features that match the elements defined in the core CityGML schema files, depending on the version selected in CityGML Version, as well as any additional ADE schema files that are specified in either the Application Domain Extension or ADE Schema File(s) parameters. Set this to Yes for new workspaces that wish to write CityGML 1.0, 1.1 and various ADE datasets.
• No – Setting this parameter to No is a deprecated option.

The writer can write elements defined in NoiseADE by setting this parameter to NoiseADE.

Alternatively, it can also write out to any other ADE by setting this parameter to Other and specifying schema files for ADE Schema File(s) parameter.

FME feature type names may include the XML Namespace prefixes used in the GML application schema. The prefix will be separated from the names by an underscore.

Setting this parameter is necessary when a GML dataset contains feature types with the same name in different namespaces.

By default, the prefixes are not added to the feature type names.

This parameter specifies additional schema files that can be used to write out elements defined in them.

Limits the number of FME nested attributes that an XML element and its children are mapped into. If the specified limit is reached, then the XML element is simply mapped into an XML fragment.

Default value: 400

By default, the CityGML writer produces UTF-8 encoded documents. If this parameter is set to another encoding, the writer will transcode the data to the specified encoding.

This parameter can be used to enter valid XML comments and will be placed in the output file after the xml declaration tag.

This parameter specifies the content of the xsi:schemaLocation attribute on CityModel root element in the output file.

Yes – CityGML restricts a curve to be a polyline. Curves should therefore be written as <gml:LineString> elements and rings as <gml:LinearRing> elements.

Setting this parameter to No is a deprecated option.

Yes – The CityGML writer will attempt to remove the auto-generated gml:id(s) (that is, gml:id(s) starting with the "fme-gen-" prefix).

Yes – The prefix for the CityGML namespace for http://www.opengis.net/citygml/2.0 or http://www.opengis.net/citygml/1.0 is set to "core".

Previously, the default namespace declaration (that is, no prefix) was always used in the CityGML output document.

The name of the subfolder to which texture files will be written, if applicable.

The name of the theme under which FME Appearances are written in the CityGML instance document.

• Yes – The CityGML XSD used for validating the output file is determined by the version specified in CityGML Version.
• No – Validation is not performed.

Specifies the preferred format for associated texture files. This preference will be used as long as the specified format supports the properties of the texture raster; if not, it will be overridden.

Possible values are:

• Auto (default) – The writer chooses the best representation based on the incoming texture raster.
• BMP
• ECW
• ERDAS
• GEOTIFF
• GIF
• INGR
• JPEG
• JPEG2000
• MRSID
• PCIDSK
• PNG
• SGI
• TIFF
• XPM

If the preferred format is ignored, a message is added to the log file. Possible reasons that the preference will be ignored include a lack of raster palette support, alpha channel support, or color depth support in the selected format.

If this parameter is set to Yes and an FME geometry entering the writer contains a non-empty xlink_href trait, the writer writes a GML geometry reference instead of a GML geometry.

For example, if a surface component, such as Face in a Composite Surface, has an xlink_href trait with value #GML_d3981803-d4b0-4b5b-969c-53f657594757, the writer writes the following geometry reference:

<gml:surfaceMember xlink:href="#GML_d3981803-d4b0-4b5b-969c-53f657594757"/>

Including the gml_geometry_reversed boolean trait with a Yes value along with the xlink_href trait causes the writer to output an OrientableSurface with a base surface geometry reference. For example:

<gml:surfaceMember>

<gml:OrientableSurface orientation="-">

<gml:baseSurface xlink:href="#GML_d3981803-d4b0-4b5b-969c-53f657594757"/>

</gml:OrientableSurface>

</gml:surfaceMember>

Setting this parameter to Yes ensures the output is neatly formatted. This promotes easier reading on screen and in print output. Note, however, that it also produces a considerably larger output file size due to the added whitespace.

• Indent Size – Select a value from 0 to 9.
• Replace Tabs with Spaces – By default the Tab character is used to for indentations. Select Yes to substitute the Tab character with a Space.

Toggle this option to reveal the coordinate precision slider.

The writer will use the value of this parameter to limit the number of decimal digits printed for each coordinate.

Valid values range from 1 to 15. The default value gives sub-millimeter accuracy when writing WGS84 coordinates. A lower number of digits can dramatically reduce the size of the output file when writing out a large number of coordinates.

This parameter has no effect on attribute values that contain floating point numbers.

Coordinate systems may be extracted from input feature data sources, may come predefined with FME, or may be user-defined. FME allows different output and input coordinate systems, and performs the required coordinate conversions when necessary.

For systems that know their coordinate system, the Coordinate System field will display Read from Source and FME will read the coordinate system from the source dataset. For most other input sources, the field will display Unknown (which simply means that FME will use default values). In most cases, the default value is all you'll need to perform the translation.

You can always choose to override the defaults and choose a new coordinate system. Select More Coordinate Systems from the drop-down menu to open the Coordinate System Gallery.

Changing a Reprojection

To perform a reprojection, FME typically uses the CS-MAP reprojection engine, which includes definitions for thousands of coordinate systems, with a large variety of projections, datums, ellipsoids, and units. However, GIS applications have slightly different algorithms for reprojecting data between different coordinate systems. To ensure that the data FME writes matches exactly to your existing data, you can use the reprojection engine from a different application.

To change the reprojection engine, Select Workspace Parameters > Spatial > Reprojection Engine. In the example shown, you can select Esri (but the selection here depends on your installed applications):

The CityGML writer will attempt to write srsName attributes on the geometry based on EPSG numbers that match the coordinate system of the features that it is writing.In some cases, no such well-know name exists. In which case, no srsName will be written. However if the user wishes to provide an srsName attribute, they can set the keyword SRS_NAME, and its value will be inserted into the srsName attribute of the geometry written.

This parameter is only used when the user is providing an srsName via the srsName parameter. It determines the coordinate order when writing geometries.

Authentication Method

Specify the authentication method to use when accessing a password-protected server.

• Basic (default) – Basic access authentication is designed to allow a client to provide credentials to a server on the assumption that the connection between them is trusted and secure. Note that any credentials passed from client to server can be easily intercepted through an insecure connection.
• Digest – Digest authentication is one of the agreed-upon methods a web server can use to negotiate credentials, such as username or password, with a user's web browser.
• NTLM – A challenge-response protocol that is used to provide compatibility with versions of Windows earlier than the Windows 2000 operating systems.
• Web Connection – Web connections provide a convenient and secure way to store and reuse previously established connection parameters. See Web Connection below.
• Single Sign-on – FME will use the credentials of the current user to authenticate the HTTP request. This authentication method currently works only on the Windows operating system.

Web Connection

Using Web Connections

FME Options: Web Connections