an IFC file (top) and the same data as CityGML (bottom)

Linking BIM and GIS

The world of BIM is getting more and more about buildings in a surrounding instead of just one building. The world of GIS is getting more and more about 3D objects and making the breach above the surface. These two worlds are getting closer to each other. The first part where these two worlds meet is CityGML. CityGML is an initiative to store semantic information about cities. The information is about buildings, but also surrounding (roads, etc) and geographic information is stored in the same standard.
The information about buildings in CityGML is very basic. Because at a city-level only the envelope of a building is interesting, there is no possibility to store information about floors, innerwalls, and other information about the inside of a building.
Luckily however CityGML gives developers the possibility to extent the standard with a specific Application Domain Extension (ADE).  BIMserver.org is developing a ADE for BIM information in CityGML. This development isn’t done in a day. We are working on it for quit some time now and it won’t be done overnight. Most important part is the transformation of the geometry. We are using the IFCEngine DLL from TNO to transform the semantic geometry of IFC to explicit geometry of GML.
The first results of this transformation are captured in a screenshot which we don’t want to keep for ourselves.
What you see is an IFC model in the free IFCbrowser (top) and the same model, transformed by the BIMserver software to CityGML in the FZKviewer.
Remember: still a long way to go….
The world of BIM is getting more and more about buildings in a surrounding instead of just one building. The world of GIS is getting more and more about 3D objects and making the breach above the surface. These two worlds are getting closer to each other. The first part where these two worlds meet is CityGML. CityGML is an initiative to store semantic information about cities. The information is about buildings, but also surrounding (roads, etc) and geographic information is stored in the same standard.

The information about buildings in CityGML is very basic. Because at a city-level only the envelope of a building is interesting, there is no possibility to store information about floors, innerwalls, and other information about the inside of a building.

Luckily however CityGML gives developers the possibility to extent the standard with a specific Application Domain Extension (ADE).  BIMserver.org is developing a ADE for BIM information in CityGML. This development isn’t done in a day. We are working on it for quit some time now and it won’t be done overnight. Most important part is the transformation of the geometry. We are using the IFCEngine DLL from TNO to transform the semantic geometry of IFC to explicit geometry of GML.

The first results of this transformation are captured in a screenshot which we don’t want to keep for ourselves.

What you see is an IFC model in the free IFCbrowser (top) and the same model, transformed by the BIMserver software to CityGML in the FZKviewer.

Remember: still a long way to go….!

2 replies
  1. Egbert Broerse
    Egbert Broerse says:

    You’ve discovered 2 weak spots in BIM, as I see it. Most of the surroundings of an object under study will never be described in 3D. What is readily available is GIS, describing the attributes of the environment as well as the physical form.
    The other GIS-theme is zooming in/out: no one is interested in all the rivets of a city district, and in an early phase of design, no one has even thought about them. How does BIM handle this?
    Please keep us updated on the progress of your application. Let’s discuss this and learn from (urban) spatial planning.

    Reply

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *