BlenderBIM: Exporting out collection instances as mapped items

theoryshaw

Is there a way to organize the BlenderBIM file such that collection instances are exported as mapped items in the IFC file?
https://gitlab.com/osarch/FreeMVD_WorkFlow/-/blob/a5b2b0dc1472ee4ffb736d4d5ca2c587016f0eb0/Random Tests/Mapped_Items/Blender_Collection_Instances/Blender_Collection_Instances_01.blend

Moult

Unfortunately, no, that is not how mapped representations work in IFC. This would be better described as a "group" (in Revit terminology) more than IFC mapped representations. There is no support for it just yet in the BlenderBIM Add-on.

theoryshaw

cool. Is there any convention in IFC for something like "mapped IfcGroups"?

Moult

https://github.com/buildingSMART/NextGen-IFC/issues/61

theoryshaw

Currently in BB, is there anyway to export out collection instances to IFC? I'm not looking to roundtrip collection instances (although would awesome) but only looking to make sure the resultant IFC file has the geometry inside the collection instances.
Or would the only way to currently get them to export is to 'make instances real', and then 'copy class', before exporting?

Gorgious

Turns out it's not really straightforward to accurately realize a collection instance. For example, if your base collection contains a disabled object, it won't be taken into account by the make_instances_real operator. Here's a discussion on BA and a script that's supposed to take care of the problems, but it seems it also has some shortcomings with boolean objects.

theoryshaw

took a stab...https://github.com/buildingSMART/IFC4.3.x-development/issues/445