Glitch at conflicting colour/material of building and building:part

[Discostu36]

Describe the bug When there is a building footprint that is not wholly covered by building:parts, but the ladder is only used to describe a part of the building that is different from the rest, the colour/material of the building and of the building:part are rendered at the same time, leading to a glitch (flickering surface).

Expected behavior The building:part should overwrite the properties of the building. In clear cases (unlike this one), it should inherit them (#98).

Map location https://streets.gl/#54.32712,10.14138,29.25,50.75,109.19

Screenshots https://www.openstreetmap.org/relation/3293733 https://www.openstreetmap.org/way/376148599

System information

• OS: Windows 11
• Browser with version: Firefox 113.0.1 (64-Bit)

Additional context In this case, the building footprint is a multipolygon, I don't know if this is part of the problem.

[Discostu36]

Another example: https://streets.gl/#54.33057,10.12366,38.25,201.00,80.94 https://www.openstreetmap.org/way/90393644 https://www.openstreetmap.org/way/984489872

[StrandedKitty]

This is expected. I don't think it's possible to make a straightforward algorithm that would detect overlapping buildings, there's just too many edge cases.

To fix this particular problem you can add building:min_level=1 to the way №376148599.