Object representation and location is not saved correctly to IFC File

Comments

• theoryshaw

  May 2023

  are you importing the IFC from another BIM program, or did you model this from scratch in BB?
• theoryshaw

  May 2023 edited May 2023

  If you modeled it from scratch i would suggest starting with one thing, perhaps the truss assembly, and seeing if it 'roundtrips' in/out of BB.
  If it doesn't, and/or the locations are wrong, i would do a videocast of your workflow, so others can see what you're doing exactly.
  I often save the IFC and reopen it in BB quite frequently, just to make sure everything looks as intended. Because, yes, these quirky things can happen... although BB's getting a lot more stable in this regard.
  ...
  Also, although i'm not 100 certain this was the cause of your problem, i would suggest creating your IfcMemberTypes, IfcBeamTypes, IfcColumnTypes, etc. with a IfcMaterialProfileSet, vs a IfcMaterialLayerSet. Allows for better miter/butt joints and you can edit the single line axis, as well.

  
• dbrundage

  May 2023

  @theoryshaw said:
  If you modeled it from scratch i would suggest starting with one thing, perhaps the truss assembly, and seeing if it 'roundtrips' in/out of BB.
  If it doesn't, and/or the locations are wrong, i would do a videocast of your workflow, so others can see what you're doing exactly.
  I often save the IFC and reopen it in BB quite frequently, just to make sure everything looks as intended. Because, yes, these quirky things can happen... although BB's getting a lot more stable in this regard.
  ...
  Also, although i'm not 100 certain this was the cause of your problem, i would suggest creating your IfcMemberTypes, IfcBeamTypes, IfcColumnTypes, etc. with a IfcMaterialProfileSet, vs a IfcMaterialLayerSet. Allows for better miter/butt joints and you can edit the single line axis, as well.

  Thank you. I clearly have lots to learn still. You were spot on. I followed your video in https://community.osarch.org/discussion/1038/blenderbim-ifc-custom-defined-beamtype-from-ifcmaterialprofileset and that worked.

  I was also having the issue of ifc entities not being deleted. Possibly from using the delete key instead of IFC Delete... wrote a script to clean it up though and it seemed to work alright....

  import bpy
  import ifcopenshell
  
  ifc_file_path = ""
  ifc_backup_path = ""
  ifc_file = ifcopenshell.open(ifc_file_path)
  ifc_file.write(ifc_backup_path)
  
  blender_object_ids = set(
      obj.BIMObjectProperties.ifc_definition_id
      for obj in bpy.context.scene.objects
      if obj.BIMObjectProperties.ifc_definition_id
  )
  
  ifc_object_ids = set(item.id() for item in ifc_file.by_type("IfcObject"))
  unused_object_ids = ifc_object_ids - blender_object_ids
  
  print("un",unused_object_ids)
  # Delete all unused objects in the IFC file
  for obj_id in unused_object_ids:
      print("id", obj_id)
      obj = ifc_file.by_id(obj_id)
      refs = set(item.id() for item in ifc_file.get_inverse(obj))
      print("refs",refs)
      ifc_file.remove(obj)
      for id in refs:
          ref_obj = ifc_file.by_id(id)
          ifc_file.remove(ref_obj)
  
  # Save the modified IFC file
  ifc_file.write("ifc_file_path")
  
  
• Arv

  May 2023

  I was also having the issue of ifc entities not being deleted. Possibly from using the delete key instead of IFC Delete... wrote a script to clean it up though and it seemed to work alright....

  @dbrundage You could also try ifcopenshell.api.run('root.remove_product', ifc_file, product=element)
  check the doc for reference