building:part when relation type=building role=outline exists


Forgive my noobish-ness. I’m attempting to define roof shape more accurately using Kendzi3D View and am experiencing challenges when building:part is surrounded with a relation type=building role=outline (a building) [to the building:part]. I don’t have height but am using building:level as a proxy. As per OpenStreetMap the outline must be tagged at the maximum level and each building:part at its respective level.

When extracting and generating LOD1 3D Buildings the result is as expected if the outline is excluded.
It matches

In Kendzi the result is the outline at maximum extrusion height. I can not even select the object.

Should role=outline not be automatically excluded in the 3D render when building:part exists? Have I tagged these incorrectly? What stupidity have I performed and how do I correct it?

(sorry; I do not know how to add an image which would explain the challenge more clearly)


edit (08/03/2021): Ok. some searching reveals this is an actual challenge that members get around through mapping for a renderer and setting the building:levels=0 when an outline exists here. Is there a permanent solution that fulfills OpenStreetMap guidelines and makes viewing in kendzi3D possible?

edit (18/08/2021): I’ve edited the Subject since this was never a rendering challenge: but rather tagging ‘relations’ correctly.

That’s not an error, but you needn’t, if there are "building:part"s.

Please show an example, that doesn’t work ( e.g. like a link like or ). By the way, this building is duplicate and should only be a relation or a way.
Probably this is the real problem.

That is a bad workaround and idea.

Thank you for helping me communicate effectively.
You are right: was not part of the relation. It displays correctly in Kendzi 3D View now.

I am a bit confused by your duplicate statement. Should the outline not be a way; part of a relation type=building? How else would the building outline be defined? How would the building:part know which outline to belong too?

This way shouldn’t have any tags. The building tags for 2D are already in the multipolygon relation.

I’ve deleted all tags from the role=outer.
This appears to solve the overpass-turbo challenge (here) where [the tags of] role=outer were coming with the query. With the tags removed the result (here) looks correct.

Your kung-fu is legend. Thank you.

Do you mind responding to OpenStreetMap help (here) please? I want to accept your answer; so that the question can be resolved.

I am incapable of defining these relations correctly. I don’t know how.

The relation and the query.

Where/how must the relation role=outline be defined so that the building:part is returned when role=outline exists?
Your help is appreciated.

edit: (31/08/2021)
building:part multipolygon relations were not accounted for - when a building:part has a courtyard.

adding: relation["building:part"]["type"="multipolygon"](area.a); to the query (line 10) fixes it.