In your first diagram, ? is min height, which is height - roof height.
In you second diagram you have two objects, each with their own height, roof height and min height, so there is more than one “?”.
min height for the lower part is 0 and min-height for the upper part is its height - its roof height. It looks like roof height for the lower part is zero.
building:part by definition defines a building part with walls and a roof. So the walls are always there!
Again, building:part is both walls and a roof!
The height of the walls is equal to height - min_height - roof:height.
The type of roof is defined by roof:shape. The roof is assumed to be flat if roof:shape isn’t set.
If the the height of the walls (height - min_height - roof:height) is equal to zero, the the building part doesn’t have walls and has only a roof.
You wanted to say, that regardless of whether a closed way has a building part(s) inside, it (that closed way) always has to be tagged with ‘building=yes’ in order to be considered to be the building (outline)? Is that it?
If it is, then I apologize for my stupid question.
If it is not?
As for the Simple 3D buildings article: I somehow have a feeling that is very short. I am not sure who wrote it, but it definitively needs to be extended.
In the last couple of topic on this forum, I learned more from your, escada, hadw and R0bst3r and other users replies then by reading that short article.
We even found out that there is important information which is not included in any wiki.openstreetmap article, let alone the Simple 3D buildings one.
Please do not take this reply as offensive, nor my intention to act as a ‘smart-ass’. I am very grateful for your free time, knowledge and patience. I am just trying to learn something, and I am getting frustrated with the lack of articles/learning material. That’s why I am trying to ask all these picky, or stupid-sounded questions.
Thank you vvoovv.
Can I again try to solve the previous two examples you gave me?
For the start, the first example:
You told me previously that:
So this is it:
?
So we know that there are walls beneath the roof, because min_height is equal to 0 (it’s not defined therefore it’s equal to 0), and the roof starts from 8 meters above the ground. So this empty space from 0 to 8 meters above the ground is assumed to be “filled” with walls?