Add 3D OpenStreetMap import

[Matthias84]

Hi, the 3dcitydb ecosystem looks great, but it might be hard to present it to cities that don't have a cityGML dataset already. Similar to 2D, the OpenStreetMap project comes to rescue 😉 and might be an useful presentation demo to the technology features.

At OSM there is an 3D mapping and 3D development community and a lot of buildings and city furnitures are already tagged with details. But for the professional GIS, we lack of a cityGML export.
As you develop a citygml4j library I suggest to start an teamwork with osm2world Java exporter that already does a lot of OSM parsing and DEM processing. And they are looking for cityGML support.

Are you interested in an cooperation? The author is currently at the FOSSGIS conference.

[clausnagel]

Hi @Matthias84, thanks for this input. I absolutely see the benefits of connecting OSM 3D with CityGML and the 3DCityDB. So, yes, we are very interested in a cooperation.

Unfortunately, I could not make it to the FOSSGIS conference this year to meet you. What would you propose as first next steps?

[Matthias84]

Thanks for your reply. I guess we need a group which starts implementing an osm2world PR that connects city2gml output to the internal models. AFAIK it's close enough. Sadly I lack of skills and time to assist. But I'm connected to the 3D folks over at OSM and will ping @tordanik if he is ok with this idea.

I guess the important point is we need somebody skilled in cityGML and your java lib. The OSM side could be covered by the OSM coders and is mostly implemented in osm2world?

[FxKu]

I was at the FOSSGIS conference but did not talk to @tordanik. The OSM saturday would have probably been a good opportunity, but I left on Friday. Still, I do not fully get the idea: OSM2world is primarily a viewer, isn't it? Why is it interesting then for OSM2World to convert it's 3D models of OSM2World to CityGML (or CityJSON)? To import it to the 3DCityDB and then export it to it's viewer? Btw: in the issue you've linked you can already find the osm2citygml tool. If you google around, you can also find more existing approaches in that direction.

I've talked about this topic several times with @kekscom from OSM Buildings but we both saw, that implementing such a bridge requires time and money ... and nobody is really screaming for it. I was also thinking, what the 3DCityDB can do for the OSM projects? Would be cool if we could offer exports to OBJ (although there already existing citygml2obj tools).

[Matthias84]

OSM2World is more than just a viewer and also supports .OBJ export. It contains a lot of functionality:

• parsing OSM files and data model
• parse simple3d buildings OSM tagging schemas
• parse OSM highways (lanes, surface, width, ...)
• apply SRTM DEM models and construct OSM
• use parameterized models for city furnitures
• use external 3D models by 3DMR
  All in all it's IMHO one of the leading tools for 3D OSM processing: https://wiki.openstreetmap.org/wiki/OSM2World

My idea is to have a unified toolset if people like to start with cityGML. Like ESRI uses OSM to offer an free basemap for their commercial products, it might be useful to offer an simple way to present OSM data in 3D to a local community. IMHO this simplifies talking about smartcities, opendata, ...
But as said, it's just an idea and I'm not able to code it...

[FxKu]

That's why I said primarily ;) I know, it does a lot more under the hood. But for the purpose to present it in the browser, right? If I got it right, in the tool chain you are suggesting, OSM2World would be only the converter. To view CityGML models one could use the 3DCityDB stack then. Not sure, if this is really of interest for the OSM2World devs. I agree, that having a powerful converter would be great. Therefore, I wonder if one could build up on @stirringhalo's work with osm2citygml. The FME-part needs to be replaced then with a pipeline like OSM2World [> OBJ] > citygml4j > CityGML. I think for a Java developer it should not be too hard to use citygml4j.

[clausnagel]

I see value in having a converter from 3D OSM to CityGML and back. I wouldn't reduce the potential use cases to just viewing the 3D data.

I am not an expert in 3D OSM and OSM2World but can contribute CityGML expertise and know-how in using citygml4j. For example, I would not recommend to convert to OBJ first but to build a converter directly on top of the 3D OSM data model if possible.

So, I would welcome a meeting with the OSM2World dev team as suggested by @Matthias84 to exchange ideas and requirements and to learn about the internal data models. Based on this exchange we will be able to estimate the efforts.

[icemagno]

What you guys have done so far? I think this could be a very useful tool. Maybe this could help.