BlenderBim Building IFC Assets

CadGiru

Have tried to model a Double Balcony door at relative high detail in Blender.
Main goal was trying to build it as an asset for BlenderBim
Got lost, when trying to decide :

• Project structure for reusable assets
• Level of detail in classifying
• Aggregation
• Type definition
• Materials
  If anybody wants to look into it and give some hints , the blend file is uploaded to gitlab

theoryshaw

I would be curious as well. Especially if it's possible to use collections within collections as you have done in your sample file.
btw... just gave you permissions to push/pull to all the OSArch repos.
Are you familiar with git?

CadGiru

@theoryshaw , thx for Your interest.
Have used both github/lab , but it is some time ago. Will have to recap.
Basically the idea was trying to start building an 'infrastructure' around blenderbim.
@duncan @Moult Would like to start a faq page on wiki. Pls ping me if You believe this is a good idea.
The thought is having this as a starting point for linking to HowTos and Tutorials

Moult

The file looks a little overengineered. Generally, a project would not go down to this level of detail and break down a door into its glazing panel and individual frames. Instead, it'll all be merged into a single "door" object. For a typical construction project, consider how it is shipped to site, scheduled, ordered from the manufacturer, and installed.

If, instead, this model was meant for a single manufacturer, feel free to break it down as you have, using aggregations.

CadGiru

@Moult This is part of a 'tutorial / self learning' project, Annex & playHouse . The aim was to be able to build a federated model with all disciplines, and several levels of detail.
In addition to a general BIM model integrating detailed 'blue collar BIM' (Don't know the correct phrase), enabling a federated model and drawings with enough detail to be used as documentation for building it. The project is small enough, yet large enough to incorporate most aspects of a BIM workflow.
Back to the door, the same philosophy has been applied, however in real life, this would be bought as a single unit.
All feedback is as always much appreciated.

brunopostle

'blue-collar BIM' - I think there is a lot of mileage in this phrase somehow

theoryshaw

How does one use aggregates with IfcDoors?
I created this file, but I think there's problems with IfcOpeningElement.
Also error below when importing.

Traceback (most recent call last):
  File "C:\Users\ryan\AppData\Roaming\Blender Foundation\Blender\2.90\scripts\addons\blenderbim\bim\operator.py", line 135, in execute
    ifc_importer.execute()
  File "C:\Users\ryan\AppData\Roaming\Blender Foundation\Blender\2.90\scripts\addons\blenderbim\bim\import_ifc.py", line 450, in execute
    self.relate_openings()
  File "C:\Users\ryan\AppData\Roaming\Blender Foundation\Blender\2.90\scripts\addons\blenderbim\bim\import_ifc.py", line 1894, in relate_openings
    building_element_global_id = self.file.by_guid(global_id).VoidsElements[0].RelatingBuildingElement.GlobalId
IndexError: tuple index out of range

location: <unknown location>:-1

Moult

That file structure looks invalid from an IFC point of view. The opening has to create the void, and then the door is linked to the opening. Whereas you have the opening and the door in one aggregate, then it looks as though the aggregate is somehow attempting to link to or create an opening in the wall.

To make it work, the opening must be outside the aggregate.

theoryshaw

I tried the following approach, but get the same error upon import. File here.

CadGiru

@theoryshaw @Moult
Learning by doing is always good, Thanks.

duncan

@CadGiru great little project. I look forward to seeing how it evolves.

theoryshaw

Related conversations: https://matrix.to/#/!FORymwGwqHJnZDpjSI:matrix.org/$QtnGID1oC_M0PfwU9xifQ9MrDOE0Bu2UkYXJwc1pgA8?via=matrix.org&via=tchncs.de&via=t2bot.io

duncan

@theoryshaw that link to matrix can only been seen if you have a Matrix account. I've pasted the bit that looked interesting in below

@csimeon wrote to @Moult : having progressed more with the testing in my pilot project, I have recorded a list of features, that imho would improve BlenderBIM.
With just 45 objects with ifc classification, the list under one IfcBuildingStorey/Reference (which is the smallest preset Spatial Element), is becoming too long to manage comfortably . My suggestions:

Implement smaller Spatial Elements that exist in Ifc protocol

• If only BlenderBIM would ignore Blender collections groupings under the IfcBuildingStorey/Reference and include the members of internal collections in the exported element set - Right now BlenderBIM does not include any sub-collections
• Parenting objects to other objects (for example a chair and a desklamp to the desk) helps and works with BlenderBIM export, as long as the children objects have their own ifc assignments. Semantically though it does not fit every need to create hierarchy and cannot be generalized.
• Archipack is onto something with parenting: each window is one object and one IfcElement, it's children, though not different IfcElements (they shouldn't be) are exported with the parent.

@theoryshaw wrote: generically, I'm also interested in how certain organizational structures like collections, parenting and aggregations, etc. hold up to roundtripping. That's basically how I prioritize how the model should be organized, that is, on how it holds up to roundtripping.
I could be wrong, but I don't think parenting holds up to roundtripping.

... and the discussion continues from there.

DADA_universe

@Moult said:
That file structure looks invalid from an IFC point of view. The opening has to create the void, and then the door is linked to the opening. Whereas you have the opening and the door in one aggregate, then it looks as though the aggregate is somehow attempting to link to or create an opening in the wall.

To make it work, the opening must be outside the aggregate.

Andrew Peel has released the first in his series of tutorials for Home Builder. The way assemblies work in Home Builder looks very promising for creating custom asset libraries. It would be super when further down the road, the Home Builder Assemblies system provides an option for building assets that automatically follow the prescribed IFC hierarchy, setting up aggregates where needed and etc on the fly.