SEPM ELE to BIM

Status

Introduction

This repository contains the code of a Python application to convert GIS data given as a GeoJSON file to an IFC file compliant with the IFC 4.3 ADD2 official schema. It's based on the IfcOpenShell Python package.

Each step described here is assumed to be executed from the home project's folder, unless otherwise specified.

Prerequisites

A machine having Docker engine 27.5.1 with Docker Compose v2.5.0 is needed to run the code.

You can get Docker here.

Note to Windows users

Please make sure you are using Docker with WSL2 (Windows Subsystem for Linux) to run Linux containers.

Preparing a file structure on the host for storing input and output data

In order to run the code on your own data, you need a place outside the home project's folder for storing both input and output data.

To do so, a file structure as follow is needed on the host:

/data
  ├── Project_Site_folder_1/
  │   └── INPUT/
  │       ├── TRACE/
  │       │   └── Strom Einfaches Trasse Achse_3D.geojson
  │       └── MESH/
  │           └── Site1_terrain_mesh.ply (optional)
  ├── Project_Site_folder_2/
  │   └── INPUT/
  │       ├── TRACE/
  │       │   └── Strom Einfaches Trasse Achse_3D.geojson
  │       └── MESH/
  │           └── Site2_terrain_mesh.ply (optional)
  └── Project_Site_folder_3/
      └── INPUT/
          ├── TRACE/
          │   └── Strom Einfaches Trasse Achse_3D.geojson
          └── MESH/
              └── Site3_terrain_mesh.ply (optional)

About custom terrain meshes

You can store custom terrain meshes in the INPUT/MESH folder inside each project.

• If you want to use those meshes, you have to set the environment variable CUSTOM_MESH=True.
• If the environment variable DOWNLOAD_TILE is also set to True, the custom mesh will take precedence.

Setting up the environment

For the code to run smoothly, you need to define a few environment variables in a .env file.

To this end, copy the env.sample file to .env: cp env.sample .env in the home project's folder and change the variables defined in this .env file according to your own environment.

The .env file MUST contain the definition of those 8 variables:

Variable	Content description
ENV	MUST be set to either DEV or PROD. However, the code is not ready yet to be deployed in a production server.
LOGLEVEL	MUST be one of the officially supported logging levels, for example DEBUG or INFO.
SHIFT_LV95_ORIGIN	MUST be set to a valid Python boolean which is either True or False. If set to False, the original coordinates will be kept as they are. ⚠️ But great care MUST be taken, because in this case, the resulting IFC file may not be correctly read by some softwares, particularly those with a 32bit architecture.
AUTHOR_NAME	MUST be the full name of the person creating the output IFC file (the author name will be stored in the IFC file). This is a header element.
AUTHOR_EMAIL	MUST be the valid e-mail address of the person creating the output IFC file (the author e-mail address will be stored in the IFC file). This is a header element.
ORGANIZATION_NAME	MUST be the name of the organization or company to which the person creating the output IFC file belongs (the organization's e-mail address will be stored in the IFC file). This is a header element.
ORGANIZATION_EMAIL	MUST be the e-mail address of the organization or company to which the person creating the output IFC file belongs (the organization's e-mail address will be stored in the IFC file). This is a header element.
AUTHORIZATION_NAME	MUST be the name of the organization authoring the output IFC file (the organization's name will be stored in the IFC file). This is a header element.
HOST_DATA_DIRECTORY	MUST be the path to the root of the data folder on the localhost. It may be given as a relative path to the project home directory.
IFC_SCHEMA_IDENTIFIER	MUST be valid schema_identifier value according to the ifcopenshell documentation.
OBJECT_NAME	MUST be the name of one of the existing properties of the features found in the GeoJSON file(s).
TRACE_FILENAME	MUST be the name (string) for the input GeoJSON trace filename. This name MUST be unique acros project folders.
DOWNLOAD_TILE	MUST be set to a valid Python boolean which is either True or False. Set to False only if you don't want to download the tiles from Internet. This is particularly useful when the tiles are already in the TEMP folder of your projects.
CUSTOM_MESH	MUST be set to a valid Python boolean which is either True or False. If set to False, the mesh will be build from the swisstopo API. ⚠️ In this case the download may take a few minutes, depending on your connection speed.

Once the .env file is correctly set up, you can move on to the next step.

Test data

There is ./tests/data folder in the project. It contains some test data that are used to demonstrate the project's feasibility.

This data should normaly build the following IFC 4.3_ADD2 file:

ISO-10303-21;
HEADER;
FILE_DESCRIPTION(('ViewDefinition[DesignTransferView]'),'2;1');
FILE_NAME('/data/Test_Project_Site/OUTPUT/IFC/pipe_lv95_3DIFC4X3_ADD2.ifc','2025-02-07T12:27:20+01:00',('Jonh Doe','[email protected]'),('Corp','[email protected]'),'IfcOpenShell 0.8.1-alpha250205','IfcOpenShell 0.8.1-alpha250205','Authorizer');
FILE_SCHEMA(('IFC4X3_ADD2'));
ENDSEC;
DATA;
#1=IFCPROJECT('0X77HvlZT1qxyuQiLXi_RO',$,'SEPM',$,$,$,$,(#10),#5);
#2=IFCSIUNIT(*,.LENGTHUNIT.,$,.METRE.);
#3=IFCSIUNIT(*,.AREAUNIT.,$,.SQUARE_METRE.);
#4=IFCSIUNIT(*,.VOLUMEUNIT.,$,.CUBIC_METRE.);
#5=IFCUNITASSIGNMENT((#4,#2,#3));
#6=IFCCARTESIANPOINT((0.,0.,0.));
#7=IFCDIRECTION((0.,0.,1.));
#8=IFCDIRECTION((1.,0.,0.));
#9=IFCAXIS2PLACEMENT3D(#6,#7,#8);
#10=IFCGEOMETRICREPRESENTATIONCONTEXT($,'Model',3,1.E-05,#9,$);
#11=IFCPROJECTEDCRS('EPSG:2056','CH1903+/LV95','CH1903+','LHN95 height',$,$,$);
#12=IFCMAPCONVERSION(#10,#11,2684146.,1247953.,469.,0.,0.,1.);
#13=IFCGEOMETRICREPRESENTATIONSUBCONTEXT('Body','Model',*,*,*,*,#10,$,.MODEL_VIEW.,$);
#14=IFCSITE('0BDGp0AbzCChZLQaIP2FMh',$,'TEMP',$,$,$,$,$,$,$,$,$,$,$);
#15=IFCRELAGGREGATES('0Yyqlybsf5$hyt4O3b9elp',$,$,$,#1,(#14));
#16=IFCPIPESEGMENTTYPE('3Jss_1lGb4cPDCnZmj6kh7',$,'NIS_pipe_segment_type',$,$,$,$,$,$,.NOTDEFINED.);
#17=IFCCARTESIANPOINTLIST3D(((-0.479,-43.28,-4.996603),(-16.282,-16.017,-2.943391),(-17.785,-6.42,-1.869175),(-16.685,0.679,-0.883098),(-11.392502,6.824456,0.34625),(-11.392502,6.824456,0.34625),(-11.082,7.185,0.394353),(-3.585,11.083,1.136873),(4.119,12.182,1.646593),(11.722,11.879,2.028708),(29.619,7.285,2.589991),(47.219,2.387,3.108823)),$);
#18=IFCINDEXEDPOLYCURVE(#17,$,$);
#19=IFCSWEPTDISKSOLID(#18,0.4,$,$,$);
#20=IFCPIPESEGMENT('12IMTWgIv6peHqmp2iDagA',$,'TAB123456',$,'NIS_pipe_segment_type',#34,#36,$,.USERDEFINED.);
#21=IFCPROPERTYSET('0wZH_JCeT1dfLtWKr2524o',$,'NIS_PipeSegmentCommon',$,(#23,#24,#25,#26,#27));
#22=IFCRELDEFINESBYPROPERTIES('3RMITm4H5EIgc9a72dyKVT',$,$,$,(#20),#21);
#23=IFCPROPERTYSINGLEVALUE('OID',$,IFCLABEL('Z-9999'),$);
#24=IFCPROPERTYSINGLEVALUE('Width',$,IFCREAL(80.),$);
#25=IFCPROPERTYSINGLEVALUE('Precision',$,IFCLABEL('Genau'),$);
#26=IFCPROPERTYSINGLEVALUE('NIS_Nummer',$,IFCLABEL('TAB123456'),$);
#27=IFCPROPERTYSINGLEVALUE('District',$,IFCLABEL('Zurich'),$);
#28=IFCRELDEFINESBYTYPE('3dBwzEgZr9SOIWJTE6jCrR',$,$,$,(#20),#16);
#29=IFCRELCONTAINEDINSPATIALSTRUCTURE('3_aHv8Sir4SPMXC6lG9VGC',$,$,$,(#20),#14);
#30=IFCCARTESIANPOINT((0.,0.,0.));
#31=IFCDIRECTION((0.,0.,1.));
#32=IFCDIRECTION((1.,0.,0.));
#33=IFCAXIS2PLACEMENT3D(#30,#31,#32);
#34=IFCLOCALPLACEMENT($,#33);
#35=IFCSHAPEREPRESENTATION(#13,'Body','SolidModel',(#19));
#36=IFCPRODUCTDEFINITIONSHAPE($,$,(#35));
ENDSEC;
END-ISO-10303-21;

which can then be opened with 3D manipulation software such as Blender using the Bonsai add-on:

Please notice that all object coordinates in the IFC file are roughly reduced to the gravity center of all points constituting the geometries.

Running the container

Finally, run the docker container using:

docker compose up -d

It can take a little while to fetch the data and build the container the very first time you execute this command, don't worry and grab a coffee ☕! The resulting image is roughly 2 GB.

After running the script, new folders will have appeared:

/data
  ├── Project_Site_folder_1/
  │   ├── INPUT/
  │   │   ├── TRACE/
  │   │   │   └── Strom Einfaches Trasse Achse_3D.geojson
  │   │   └── MESH/
  │   │       └── Site1_terrain_mesh.ply (optional)
  │   ├── TEMP/
  │   └── OUTPUT/
  │       └── IFC/
  ├── Project_Site_folder_2/
  │   ├── INPUT/
  │   │   ├── TRACE/
  │   │   │   └── Strom Einfaches Trasse Achse_3D.geojson
  │   │   └── MESH/
  │   │       └── Site2_terrain_mesh.ply (optional)
  │   ├── TEMP/
  │   └── OUTPUT/
  │       └── IFC/
  └── Project_Site_folder_3/
      ├── INPUT/
      │   ├── TRACE/
      │   │   └── Strom Einfaches Trasse Achse_3D.geojson
      │   └── MESH/
      │       └── Site3_terrain_mesh.ply (optional)
      ├── TEMP/
      └── OUTPUT/
          └── IFC/

The TEMP folder inside each project's folder will containg temporary data. It can safely be deleted.

The OUTPUT/IFC folders in your project directories is were you can find the resulting IFC files.

Extras

If need be you can check the logs with:

docker compose logs -f app

To kill the container:

docker compose down

License

This package is released under the GNU General Public License version 3, 29 June 2007

SPDX short identifier: GPL-3.0-only

OSI link.

Third Party Licenses

This package relies on many third party libraries. Please, carefully read the NOTICE.md file.

Going futher

Feel free to have a look at the Wiki if you want to go further.