Object representation and location is not saved correctly to IFC File

D by dbrundage on 9 May 2023, edited 15 May 2023 #

When I import my IFC file into a new project many of my objects do not have the correct representations of locations and some deleted objects are still in the ifc file. Any ideas? I know I must be missing a some steps in the process...

T by theoryshaw on 9 May 2023 #

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

T by theoryshaw on 9 May 2023, edited 9 May 2023 # +1 votes

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.

D by dbrundage on 10 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")

A by Arv on 15 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