CityGML-specific export options¶

The CityGML exporter in the citydb-tool provides options specific to exporting data in the CityGML format. These options allow users to customize version compatibility, apply transformations, and manage feature mappings.

CityGML-specific options¶

Option	Description	Default Value
`-v`, `--citygml-version=<version>`	Specify the CityGML version for the export: `3.0`, `2.0`, or `1.0`.	3.0
`-x`, `--xsl-transform=<stylesheet>`	Apply one or more XSLT stylesheets to transform the exported CityGML file. Separate multiple stylesheets with commas.
`--use-lod4-as-lod3`	Replace existing LoD3 geometries with LoD4 geometries during the export.
`--map-lod0-roof-edge`	Map LoD0 roof edge lines onto roof surfaces for better representation in the output.
`--map-lod1-surface`	Map LoD1 multi-surfaces onto generic thematic surfaces to simplify LoD1 geometries.

Examples for CityGML export options¶

Below are practical examples demonstrating how to use CityGML-specific options in the citydb-tool.

1. Export with a specific CityGML version¶

To export data in CityGML version 2.0 format:

citydb export citygml -o output_v2.gml --citygml-version=2.0

Apply XSLT stylesheets for transformation¶

To apply one or more XSLT stylesheets during the export process:

LinuxWindows

citydb export citygml \
       -o transformed_output.gml \
       --xsl-transform=transform1.xsl,transform2.xsl

citydb export citygml ^
       -o transformed_output.gml ^
       --xsl-transform=transform1.xsl,transform2.xsl

This applies transform1.xsl and transform2.xsl sequentially to the export.

Replace LoD3 with LoD4 geometries¶

To replace existing LoD3 geometries with LoD4 geometries during the export:

citydb export citygml -o lod3_output.gml --use-lod4-as-lod3

Map LoD0 roof edges to roof surfaces¶

To include LoD0 roof edge lines as part of roof surfaces in the export:

citydb export citygml -o lod0_with_roofs.gml --map-lod0-roof-edge

Map LoD1 multi-surfaces to generic surfaces¶

To restructure LoD1 multi-surfaces into thematic surfaces for better alignment:

citydb export citygml -o lod1_mapped_output.gml --map-lod1-surface

This simplifies LoD1 geometries for tools that require a clearer surface structure.