Triply Use Case 8: GeoSPARQL profile for IFC

[wouterbeek]

Triply Use Case 8: GeoSPARQL profile for IFC

Description

A lot of 3D data is stored in IFC. In the future, GeoSPARQL will have the ability to detect or configure the following aspects of 3D BIM data:

• The position, see Triply Use Case 4: Align an engineering CRS to a geospatial CRS #586 .
• The height, see Triply Use Case 5: Place 3D data at the correct height #587 .
• The angle, see Triply Use Case 6: Place 3D data at the correct angle #588 .
• The size, see Triply Use Case 7: Place 3D data in the correct size #589 .
• The texture, see Triply Use Case 2: Support for textures #584 .

IFCs are able to encode this data, but many IFC files do not include all this information. GeoSPARQL should include a profile for IFC, that allows users to quickly check whether an IFC is eligible for GeoSPARQL inclusion. The profile should check for the information properties that are used in GeoSPARQL to place a 3D object in a correct way. If the profile is followed, translation from IFC to GeoSPARQL is guaranteed to work (assuming the entered values in the IFC are correct).

Such profiles are called "Informatieleveringsspecificaties" or "ILS" in The Netherlands.

Actor

• Data Expert (who may not be a Geodata Expert)

Preconditions

• I have an IFC file.
• I have some GeoSPARQL data.

Postconditions

• I have integrated my IFC 3D data into my GeoSPARQL data. I was able to do this in a modern triple store, without having to write any code.

Steps

1. I have an IFC file.
2. I use the GeoSPARQL profile for ILS to determine whether my IFC will automatically translate to GeoSPARQL 3D.
3. The profile indicated that my ILS lacks a geospatial reference.
4. I update my ILS to include a geospatial reference (or I ask the geospatial expert who gave me the ILS to change this for me).
5. When I use the GeoSPARQL profile for ILS again, I now pass all the profile checks. I can therefore add my ILS to a triple store that automatically stores it as GeoSPARQL 3D.
6. When I query my data, I can confirm that the ILS data now appears at the right spot, at the right height, in the right size, under the right angle, and with the correct textures applied.
7. I now upload a batch of 100 IFC files. 5 minutes later, I have a whole neighborhood of 3D buildings in my triple store, that others can query.

[FransKnibbe]

Some notes:

1. IFC is a data exchange format for BIM.
2. ILS are text documents, but they can have machine-interpretable specifications: IDS. An IDS could include specifications on how to make IFC data interoperable with geoSPARQL.
3. IfcOWL is a web ontology for IFC, but it does not use GeoSPARQL. Not all IFC geometry can be easily mapped to GeoSPARQL, but some of it might.