They are. This is to be flexible. Lots of building types may not have levels but other geometric boarders than levels to splitt them into pieces, thus the building part was indroduced.
yorik wrote: ↑
Sat Jan 05, 2019 7:23 pm
yes, the "basic" use of Building Parts is to make levels (or storeys, floors, whatever). But being forced to divide your building into levels always annoyed me. What of an elevator shaft, for example? Or a glass curtain façade? Of course you can "fake" making a separate level only for it. But that's not correct semantically.
I agree, I think the concept of levels is more semantically related to representation (since we experience buildings floor by floor, and so they perfectly identify plan views for example) than to group building components (that have more sense to follow other rules, the ones of construction for example, as workers will first build storeys and at the end add a curtain facade).
So the Building Part is basically a grouping of BIM objects. By setting its IFC role to "Building" or "Building Storey", you turn it into a building or a level, simple as that.
Perfect to me.
At the moment, they behave like a group, that is, an object can only be inside one BuildingPart. But we could also easily remove that restriction, I'm actually not sure if it's a good thing or not...
I think this is again correct. it forces a bit to be tidy, but that's not bad. Again it would be good to control in views which part has to be shown or eventually which components in the part.
But there is another important feature too, BuildingParts have a Shape property, that is a compound of all its children. So they are basically a hybrid between a group and a part object. So they can be cloned, referenced in another file, etc. The idea is that you can also use BuildingParts to make repeatable components, such as a bathroom stall. If you set their IFC role to Element Assembly, they are exported as such to IFC, and reimportable as is.
But the main workflow I see is that you would use a BuildingPart as a level, work inside it (place it correctly, look at it from the angle you wish, right-click it in the tree view -> Write camera position, set its "Restore view" to True, and when you activate it, you'll find yourself all set, in that view. I'm planning to add an implicit section plane to it too (you can specify the height/offset), and the possibility to hide all other objects while you're working in (same as WPProxies). And maybe the possibility to cut the view, like the section plane does, but I'm not sure if it will still be practical to work with, that needs testing.
That sounds very good.
What misleaded me about building parts and levels is that the icon in the tree was slightly different