How do I convince OsmAnd that these buildings share a wall?

grawity · 2024-09-10T07:21:42.102Z

For my first day contributing to OSM, I tried to split the building at 55.499, 25.602 into two objects, to reflect recent changes in ownership: half of the building is now privately-owned, and although the two parts still share a wall, they officially have different addresses (due to entrances from different streets).

The result seems to be fine when viewed via JOSM or the web interface:

Screenshot from 2024-09-10 10-12-351948×1078 249 KB

But for some reason, OsmAnd renders a gap between the two areas:

Screenshot_20240910-101055|243x500, 75% Screenshot_20240910-101101|243x500, 75%

What needs to be done to glue the two objects together?

Fizzie41 · 2024-09-10T07:58:36.738Z

Could you please give us an OSM link so we can have a look at them?

PHerison · 2024-09-10T08:08:38.393Z

Coordinates from screenshot: OpenStreetMap

whb · 2024-09-10T09:29:23.806Z

grawity:

But for some reason, OsmAnd renders a gap between the two areas:

Your mapping is correct.
This is a bug in OsmAnd rendering that can occur whenever two objects share a node, but this node does not belong to a corner of both objects.
This node Node: 3015670113 | OpenStreetMap is a corner of Way: ‪Utenos DSC sporto centro salė‬ (‪1313672033‬) | OpenStreetMap but not of Way: ‪RL GYM Sporto Klubas‬ (‪297680985‬) | OpenStreetMap (it is only part of the line).
Due to the line simplification, this node is then omitted for Way: ‪RL GYM Sporto Klubas‬ (‪297680985‬) | OpenStreetMap. Due to the rounding of the node coordinates (to save storage space), a gap then appears at high zoom levels.

Gertjan_Idema · 2024-09-10T11:42:15.847Z

From what I read in you comment, it is still one building in the real world. Internally it has been split in 2 parts, which can be represented by adding outlines for the internal parts tagged with building:part. The addresses can be tagged on the building parts or on separate address nodes.
So in my opinion, you shouldn’t split this building. Just like we wouldn’t split the Burj Khalifa (Dubai) in over a 1000 separate buildings because there are this many apartment and offices. I know this is an extreme example, but the concept is the same. One building in the real world <=> one building in Osm.

whb · 2024-09-10T13:46:12.069Z

Gertjan_Idema:

From what I read in you comment, it is still one building in the real world.

Looks more like two buildings to me:

mapillary.com

Mapillary

Street-level imagery, powered by collaboration and computer vision.

mapillary.com

Mapillary

Street-level imagery, powered by collaboration and computer vision.

Can also be seen on a source not allowed for OSM:
https://maps.app.goo.gl/teuDTDLBiaK1Kdv69

grawity · 2024-09-10T15:12:28.519Z

Gertjan_Idema:

So in my opinion, you shouldn’t split this building. Just like we wouldn’t split the Burj Khalifa (Dubai) in over a 1000 separate buildings because there are this many apartment and offices. I know this is an extreme example, but the concept is the same. One building in the real world <=> one building in Osm.

I actually assumed that such splitting is standard practice because of the large amount of instructions on using the Terracer/Uberterracer plugins for JOSM to do this exact thing?

Jarek · 2024-09-10T16:09:34.435Z

grawity:

I actually assumed that such splitting is standard practice because of the large amount of instructions on using the Terracer/Uberterracer plugins for JOSM to do this exact thing?

I don’t know if there is such a thing as “standard practice” in OSM, but it is certainly very common. See for example Way: 606066930 | OpenStreetMap and surrounding area in Berlin which has buildings that are connected to each other and which share very similar massing and construction, mapped as separate buildings according to their access details, street address, and I guess ownership.

Gertjan_Idema · 2024-09-18T15:51:59.109Z

From the reactions I realize that I was a bit to much focused on the situation in The Netherlands. Here, almost all buildings have been imported form official government sources, so splitting and the Terracer plugin are hardly ever needed.
You can ignore my previous comment.

grawity · 2024-09-18T17:10:10.049Z

So I actually looked at official government sources a bit later (that is, when I learned about geoportal.lt, which I believe LT buildings were once imported from).

If I understand this correctly (though it’s likely that I don’t), the official government sources do split the building – the “GPRK” layer shows the same line I drew (coord link):

image1194×870 136 KB

The land cadaster map has an even weirder split that goes sideways, which doesn’t make any sense for that building’s internal layout, but from what I’ve heard it just…happened somehow:

image1194×870 158 KB

This split happened somewhere around 2019-2021, but I suppose there is no auto-reimport or anything so the old footprint remained.

whb · 2024-09-19T10:46:09.498Z

grawity:

but I suppose there is no auto-reimport or anything so the old footprint remained

OpenStreetMap

Way History: ‪RL GYM Sporto Klubas‬ (‪297680985‬)

OpenStreetMap is a map of the world, created by people like you and free to use under an open license.

source=ORT10LT means orthophoto, so it was probably not an import:
https://wiki.openstreetmap.org/wiki/WikiProject_Lithuania/Contributors

whb · 2024-09-19T11:08:30.542Z

grawity:

If I understand this correctly (though it’s likely that I don’t), the official government sources do split the building – the “GPRK” layer shows the same line I drew

Yes, the official government source splits the building exactly as you did.

grawity:

The land cadaster map has an even weirder split that goes sideways, which doesn’t make any sense for that building’s internal layout, but from what I’ve heard it just…happened somehow:

The red lines show the property boundaries. These have no effect on the building outlines.

জাবির · 2024-09-20T02:38:48.252Z

I don’t know but osmand renderer has issues, I’ve seen perfectly squared adjacent buildings renders uneven.

Robert46798 · 2024-09-20T04:35:21.016Z

And it’s not only about buildings

Screenshot_2024-09-20-06-34-05-159_net.osmand.plus-edit1080×1979 91.6 KB