Rinalds L. (Aug 31 2026 at 20:10): Rinalds L. (Aug 31 2026 at 20:10):I would like to know why buildings appear slightly not square when zoomed in even if they are squared using josm Q tool. It appears slightly unsquare on all popular osm apps like comaps, osmand for example.
Rinalds L. (Aug 31 2026 at 20:11):And it only happens on buildings with narrow stuff. A simple rectangle is fine
markalex (Aug 31 2026 at 21:18):I'm not sure I get what you are saying. I checked some random building in CoMaps, and it looks rectangular enough to my eye.
Can you show an example, maybe with screenshots?
How did you check "rectangularity" in app?
Rinalds L. (Sep 01 2026 at 04:34):Even in riga. I always see something like this on buildings, slightly skewed1000049879.png
Rinalds L. (Sep 01 2026 at 04:41):I am not sure is that a projection issue or app render issue because if you would look at it in an editor for example it would not be skewed
markalex (Sep 01 2026 at 04:48):I mean specifically Purvīša 15 is not squared. Inset cornet is not parallel to other walls, and whole shape is not squared.
Rinalds L. (Sep 01 2026 at 04:51):Hm alright, maybe it just is actually unsquare buildings
Colby (Sep 01 2026 at 06:38):osmand doesnt store coordinates as precise as carto
with pre-rendered raster tiles it doesnt matter but when doing vector tiles you have to make some compromises to have good performance
shortbread and maptiler omt on the OSM website have the same issue
https://xkcd.com/2170/
Rinalds L. (Sep 01 2026 at 06:40):Ohhh yep, thanks for explaining!
kaposts (Sep 01 2026 at 08:45):Not just coordinate precision, some maps simplify the polygons by removing nodes. This can be easily observed on openstreetmap website by switching between standard tileset and shortbread. Usually not a problem but unlucky node removal can sometimes cause visible distortions for shapes that don't have too many corners or when other nearby shapes serve as reference .
Last updated: Sep 10 2026 at 11:46 UTC