johnsamuelwrites / udv-server

UDV-server

UDV-server is a collection of server-side tools for converting and analysing urban data. The client-side component can be found here.

Version number is defined in setup.py.

For an install of the full pipeline of our application, please refer to these install notes.

Tools

API_Enhanced_City

TODO

Please visit this page in order to install this tool.

ExtractCityData

Introduction

This tool allows to process a 3DCityDB database to create a materialized view on buildings of the database containing their id, their geometry and optionnally their year of construction and year of demolition.

Use

Activate venv if you created one: . venv/bin/activate

You can run python extract_city_data.py -h to display help about this tool.

extract_city_data.py takes one mandatory argument and one optionnal argument.

The first one is a configuration file for the database such as ExtractCityData/db_config.yml:

PG_HOST: <server hosting your db>
PG_USER: <your db user name>
PG_PORT: <port>
PG_PASSWORD: <user password>
PG_NAME: <database name>
MATERIALIZED_VIEW_NAME: <name of the output materialized view>

You must fill these information. Note: MATERIALIZED_VIEW_NAME must start with a letter.

It also takes an optionnal argument : -t or --temporal. If set, the materialized view will also contain the years of constructions and years of demolitions of the buildings.

Note: Once created, the view can be refreshed using REFRESH MATERIALIZED VIEW name. More information here

Design

We had the choice between using a view, a materialized view or a new table (possibly in a new database) to store the output result.

We didn't choose a view because the output needs to be persitent in order to be used by another program (py3dtiles).

We chose a materialized view over a new table because the update process is easier and because we didn't want to modify the database schema of our 3DCityDB database. In addition, it is implemented in PostGIS since v9.3.