Object representation and location is not saved correctly to IFC File

dbrundage

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...

theoryshaw

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

theoryshaw

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

@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

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