Please check the mapping before giving links to such a mess:
most roof:height are missing so it gives different rendering between projects (on F4Maps most of wall are screwed because generated roof:height is higher than heigh-min_height)
roof:colour=#cococo i think using “0” would be better for a color than “o”
height=0.1 on building outline with higher parts (outline height should be the max height of every parts)
many dupplicated nodes, overlapping buildings and other JOSM Warnings
most roof:height are missing
This is because roofs have been digitized separately than buildings. Since roofs cover much larger area than the building, atleast twice as large. So roofs are made as buildings without the lower part.
generated roof:height is higher than height - min_height
This is because there is no support for trapezoidal roof, Pyramidal roof are made by giving higher value for roof:height and then another structure is used to cover up the extra part. Since values are not exact, there are some mismatches.
roof:colour=#cococo
This has been corrected.
many dupplicated nodes, overlapping buildings and other JOSM Warnings
duplicated nodes have been corrected, but there are no overlapping buildings.
a lot of building:part are outside the building outline and so won’t display.
same problem for the ceiling, it’s too big compared to outline so it’s not included in the building. also outline includes a hole in the middle, explaining the loss of middle stuff!
for the part that looks like ceiling, it’s the outline leftovers, use building:part=no to remove it.
I noticed that a lot of buildings (including the last one) are not connected to some high level relation. Is it just because of “work in progress”? I’m working on my generator for Unity3D and it is quite important to group all parts by one relation so that I can create one Unity’s GameObject instead of hundreds. This is major performance optimization f and also this way I can interact with the building as single mesh which is quite important from business logic. For example, I like this one:
Dear Felis Pimeja,
fantastic model, great job in Grozny!
Dear eis_kalt, that´s true, the Siena Cathedral is still in progress.
Could you be so nice and add your hint into the subpage: http://wiki.openstreetmap.org/wiki/Simple_3D_buildings#Building_relation.
Maybe a link to an other Page with examples showing what happens with 3D model without building relation.
I think the existing text is clear enough, and mentioning examples of application-dependent behaviour would not improve it.
In fact, I believe that applications should not rely on the existence on the relation, given how a large number of 3D buildings already do not use a building relation. It’s not really a problem to algorithmically determine which building parts belong to a building. At this point, encouraging the use of the relations (except in the very few cases where they are actually necessary, e.g. overlapping buildings) only makes 3D mapping look more complicated than it actually is.