Missing wall and floor for some solid swissBUILDINGS3D data

[francois bourdon]

Hi all,

I am using  swissBUILDINGS3D data, solid representation (roof+building)

Looks like modelisation depends on the area:

- for example, the complex roof of the church in Finhaut is made of one single element (fine for me !)

- but in Bern complex roofs are made of multiple elements (not good for me, I don't know how to match roofs and buildings)

- worst case in Geneva, building meshes are only roofs, no wall and no floor ! (same in .gdb or .dwg files)

You can easily check the "Geneva problem" by opening swissbuildings3d_3_0_2020_1301-13_2056_5728.dwg.zip (choose solid dwg) in Autocad: no wall and no floor for buildings 

Hope it is clear, what am I doing wrong ?

François

[David...@swisstopo.ch]

Hi

I forwarded this to swisstopo geo...@swisstopo.ch

 

They will answer this question directly…

 

 

Best regards

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[Patrick Aeby]

 Dear François

swissBUILDINGS3D 3.0 is currently only available in a beta version. We are aware that there are in the entire dataset still some tiles with problems, which could not be properly derived. Tile 1301-13 in Geneva is one such tile. In tile 1301-13, unfortunately, the floors and walls are indeed missing. We are constantly trying to improve the dataset and are confident that we will be able to offer the desired quality when the “beta” period ends. So you did nothing wrong when you imported tile 1301-13. The problem we have with this tile lies with us.

You are also right about the modeling of swissBUILDINGS3D. For the 3D model of the large cities of Zurich and Bern, we used the 3D city models of these cities as the basis for swissBUILDINGS3D. Cities usually create their models at a higher level of detail than we do it for our countywide dataset. This also explains why the large cities have more detailed geometries in swissBUILDINGS3D than other regions in Switzerland.

Furthermore, in swissBUILDINGS3D 2.0 and 3.0 Beta the modeling of a building is determined with the acquisition of the roof, independent of how the building is divided by EGID (Federal building identifier). This can lead to the fact that the allocation between roof and building body is not always evident. With the further development to swissBUILDINGS3D 3.0, we will split the building models and the roofs according to EGID. This means that roofs can be clearly assigned to a building body via the EGID soon. 

If you are interested: the newsletter geodata-news 48 contains useful information on the further development of swissBUILDINGS3D (in German and French) - also on the issue of EGID.

https://www.swisstopo.admin.ch/de/swisstopo/publikationen.detail.publication.html/swisstopo-internet/de/publications/topo-publications/geodata-news_48_2022.pdf.html

Best regards,

Patrick

[francois.b...@gmail.com]

Dear Patrick,

 

Thanks very much for your detailed answer, it is clear !

 

I new the newsletter (french version for me 😊), and I fully understand swissBUILDINGS3D 3.0 is a Beta version, I was just wondering if I was doing something wrong

 

Adding EGID will be a great improvement for sure

 

Thanks again, have a great day,

 

Best regards,

François

 

 

De : geoadm...@googlegroups.com <geoadm...@googlegroups.com> De la part de Patrick Aeby
Envoyé : mercredi 22 juin 2022 09:54
À : GeoAdminCh API <geoadm...@googlegroups.com>
Objet : Re: Missing wall and floor for some solid swissBUILDINGS3D data

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