Talk:Key:building:part

Distinct 3D and 2D map easier

Little proposal for mapping 3D building: If the building is simple (house, tower) and just need to map the roof, enter building:levels in the building tags. But Is the building is complex (different level) just map the building and enter the building:levels in building:part and don't enter the main building as building:part

Why? because for routing apps, for example, if lightweight map are needed it is easier to remove all the relation with the tag building:part.

It sounds to me like you're describing the Simple 3D buildings schema? If not, you should probably clarify your idea and take it to that page. Neuhausr (talk) 12:50, 22 April 2016 (UTC)

When ou have a look to Empire State Building the base is map as building:part and in my proposition only 3D part should have the key building:part, not the base. This could help when export the data: it's easier to make the distinction beetween 2D and 3D building.

That's incorrect tagging, though. Right now, the tagging tells me that the Empire State Building has 5 levels total and is 17 meters high... --Tordanik 19:03, 23 April 2016 (UTC)

That's a problem then, because it's one of the example provided... another problem is a difference in building interpretation by 3D software, have a look to OSMBuildings and F4map the roof interpretation differ while it's the same building, then how can is choose the correct 3D mapping ? --Homer simpsons (talk) 14:36, 24 April 2016 (UTC)

Precise if a "building=*" should be rendered or if it's replaced by its "building:part"s

The tag "building:part" is a good idea, but nothing links the mait building polygon to the parts... It would be easier for a renderer to know, for a specific "building" polygon, it it should be rendered or if that's already been done by rendering the "building:part"s... So I think we need either to make a building relation, or at least to add a tag on the building that should not be rendered if the building:parts are renedered, maybe something like render=parts --Clementrouxosm (talk) 12:31, 12 August 2019 (UTC)

It would be easier for a renderer, but it would also mean extra manual work for every single building that has parts. I'd rather invest a little extra effort in coding this once and have it taken care of automatically from then on. --Tordanik 17:16, 23 August 2019 (UTC)

how to add bulding min levels without change the roof of the building?

i try to add 3d info for buildings near of my home but i can't do house with a bulding part with building minlevels witouth have a modification on the roof rended of the building https://demo.f4map.com/#lat=44.3676226&lon=2.5940471&zoom=21&camera.theta=58.228&camera.phi=81.178 https://www.mapillary.com/app/?login=true&lat=44.36778305555555&lng=2.594298055555555&z=18.33266209576741&username%5B%5D=yod4z&pKey=EE3CeLwqJiX5NOnMyS0OPg&focus=photo&tab=uploads. And how to render building with balcony and only roof on top(balcony at the first level and roof of the building on the second level). thanks for the help-Yod4z (talk) 17:54, 13 November 2020 (UTC)

Can you post direct link to photo of a specific building? Or with marked specific building? Not sure which building you want to map. Note also, that it is possible that f4map will not work with a correct tagging Mateusz Konieczny (talk) 22:02, 13 November 2020 (UTC)

https://www.openstreetmap.org/way/148371813 this building with building minlevel https://www.openstreetmap.org/way/868740460 aand on f4map the roof is not the building with the tag roof but the same apply to the building:part-Yod4z (talk) 09:09, 16 November 2020 (UTC)

This tagging is correct, you can try contacting whoever operates F4 to improve their renderer Mateusz Konieczny (talk) 09:15, 16 November 2020 (UTC)

I don't think F4 is wrong. Each building part will have its own roof. So if you want a single roof, you can usually achieve that by splitting the building into parts vertically (parts on top of each other). --Tordanik 20:32, 29 November 2020 (UTC)

Usually add building relation?

This page says "It is also recommended to use a type=building relation to group together the outline way and the building:part=yes ways." The simple 3D building page suggests you shouldn't unless a part overlaps the footprint as does the building relation page. Should this page be updated? TrekClimbing (talk) 13:24, 21 May 2021 (UTC)

I support updating this page. --Tordanik 16:45, 24 May 2021 (UTC)

So do I. --Chris2map (talk) 17:50, 24 May 2021 (UTC)

Thanks. Now edited. TrekClimbing (talk) 20:31, 25 May 2021 (UTC)

building:part always contained in building?

Should a building:part always be fully enclosed by way tagged with building? The sentence "building:part=* areas should be always within a separate building=* area representing the entire building." sounds like this. But later it is said: "If any of the building:part=* areas are not completely inside the outline of the whole building=*, it is also recommended to use a type=building relation to group together the outline way and the building:part=* ways." Why does not sound like a way tagged building:part should always be full enclosed... Can somebody clarify? And when is the relation required/recommended? --Ze0zohk1 (talk) 18:56, 28 July 2021 (UTC)

re fractional

https://wiki.openstreetmap.org/w/index.php?title=Key:building:part&curid=89059&diff=2180637&oldid=2178423

"* building:levels=* – number of levels in this part, also possible fractional values, e.g. 1.5" - what is the meaning of fractional levels? @Maro21: Mateusz Konieczny (talk) 07:30, 29 July 2021 (UTC)

Fractional values are in common use in 3D tagging. The height of buildings (in meters) is difficult to determine if you don't have the right data, e.g. from a cadastre. The number of levels is a relative value - you know only how many levels a building has and when you draw [building:part]s, you give their relative number of levels in relation to the whole building. maro21 20:21, 29 July 2021 (UTC)

Fractional levels have no properly defined meaning and shouldn't be used. In 3D rendering, the number of levels is needed for multiple purposes, such as:

• Interpreting objects with a level=* correctly, such as entrances and any indoor mapping.
• Displaying as many rows of windows as there are levels.
• Estimating the height if there's no height=* tag.

Fractional levels break most of these purposes except height estimation, and there are better solutions for goal. (Just tag an estimated height, it's ok!) --Tordanik 21:17, 2 August 2021 (UTC)

Chimneys

Mention how to use building:part=* when a chimney's height doesn't reach man made=chimney minimums. Jidanni (talk) 13:55, 22 November 2022 (UTC)