CityGML Parser

CityGML 3.0 (Python version) parser for reading, writing, and converting CityGML files into JSON using Python. Since there is no suitable, easy-to-use, Python-based CityGML 3.0 parser available, I developed this. In the future, this parser is planned to be used to physically implement ISO/TS 19166 BIM-GIS conceptual mapping. In addition, if you need landxml parser (python version), refer to landxml parser. The parser function will be further updated.

🚀 Features

Version 0.1

Parse CityGML 3.0 files into Python objects.
Modify CityGML objects and write back to XML format.
Convert CityGML to JSON for easier data processing and integration.
Convert CityGML to MESH (under development).
Download CityGML 3.0_parser class with members HTML document

house

building

building

road

city

difference between input and output citygml

Next Plan

Support CityGML 2.0. In addition, there is citygml2 to citygml3 convertor. It's working.
Fix name space problem

📂 Installation and usage

To install the required dependencies, run:

pip install numpy xsdata lxml pdoc trimesh shapely

Converter usage

python citygml_json --input ./sample/CityGML_3.gml --output ./CityGML_3.json
python citygml_converter --input ./sample/CityGML_3.gml --output ./output.gml

📄 Usage

📍 1. Read a CityGML File

from citygml_parser3 import *
from xsdata.formats.dataclass.parsers import XmlParser

# Initialize parser
parser = XmlParser()

# Parse CityGML file
model = parser.parse("./sample/1_SimpleBuilding/CityGML_3.gml")

# Print parsed model
print(model)

📍 2. List CityGML buliding and surface information

city_objects = model.city_object_member

for city_object in city_objects:
	building = city_object.building

	print(f'building id: {building.id}')
	print(f'building name: {building.name}')

	try:
		for bound in building.boundary:
			wall = bound.wall_surface
			if wall:
				print(f'wall id: {wall.id}')
			roof = bound.roof_surface
			if roof:
				print(f'roof id: {roof.id}')
			floor = bound.floor_surface
			if floor:
				print(f'floor id: {floor.id}')
			ground = bound.ground_surface
			if ground:
				print(f'ground id: {ground.id}')
			
		if building.lod1_solid:
			print(f'building lod1_solid')
			for sf in building.lod2_solid.solid.exterior.shell.surface_member:
				print(f'surface: {sf.href}')			
		if building.lod2_solid:
			print(f'building lod2_solid')
			for sf in building.lod2_solid.solid.exterior.shell.surface_member:
				print(f'surface: {sf.href}')
		if building.lod3_solid:
			print(f'building lod3_solid')
			for sf in building.lod2_solid.solid.exterior.shell.surface_member:
				print(f'surface: {sf.href}')
		if building.lod4_solid:
			print(f'building lod4_solid')
			for sf in building.lod2_solid.solid.exterior.shell.surface_member:
				print(f'surface: {sf.href}')
	except Exception as e:
		pass

result

📍 3. Modify and Write CityGML File

from xsdata.formats.dataclass.context import XmlContext
from xsdata.formats.dataclass.serializers import XmlSerializer
from xsdata.formats.dataclass.serializers.config import SerializerConfig
from pathlib import Path

config = SerializerConfig(indent="  ")
context = XmlContext()
serializer = XmlSerializer(context=context, config=config)

# Output file path
path = Path("CityGML_3_output.gml")

# Write back to CityGML format
with path.open("w") as fp:
    serializer.write(fp, model)

📍 4. Convert CityGML to JSON

You can convert CityGML files to JSON format using the included citygml_json.py script.

📌 Convert via Command Line

python citygml_json.py --input_file ./sample/CityGML_3.gml --output_file ./CityGML_3.json

📌 Convert using Python

from citygml_json import convert_citygml_to_json

input_gml = "./sample/CityGML_3.gml"
output_json = "./CityGML_3.json"

convert_citygml_to_json(input_gml, output_json)
print("CityGML successfully converted to JSON.")

📍 5. Convert CityGML to MESH (under development)

You can convert CityGML to MESH format. It supports building's boundary, lod solid which consists of polygon surface.

python citygml_mesh.py --input_file ./sample/ManhattanSmall.gml --output_file ./ManhattanSmall.glb

📂 Project Structure

citygml_parser/
│── citygml_parser3/       # CityGML parsing module
│── sample/                # Sample CityGML files
│── docs/                  # manual
│── citygml_parser_example.py  # Example 
│── citygml_converter.py  # CityGML conversion 
│── citygml_json.py       # CityGML to JSON conversion
│── citygml_to_mesh.py    # CityGML to Mesh conversion 
│── README.md             # Project documentation

👤 Author

Name: Taewook Kang
Email: [email protected]

📜 License

This project is licensed under the MIT License.

🙌 Acknowledgments

This project is inspired by CityGML 3.0, an OGC standard for 3D city modeling.

citygml_parser

README