Issue with renaming My Storey

P by pederlh on 20 Dec 2023, edited 21 Dec 2023 #

Hi,

I am trying to rename the default storey that is created when initializing an IFC project in Blender, and I wish to do this through running a Python script. However, whether this succeeds or not seems to depend on if the script is run from within the Blender UI or if the script is provided when running Blender from the command line.

I have an example file which should reproduce the problem. If the following snippet is run from the Scripting tab in Blender, the storey seems to be renamed properly. What I try to do is to do the renaming, set the storey as the (current) parent colelction, assign ifc classes to some objects, and link the ifc components to the storey:


import bpy


bpy.ops.bim.create_project()

bpy.ops.mesh.primitive_cube_add(

    size=2, enter_editmode=False, align="WORLD", location=(0, 0, 0), scale=(1, 1, 1)

)


storey_name = "Floor 1"


# Rename collection / Storey object

old_collection_name = "IfcBuildingStorey/My Storey"

if old_collection_name in bpy.data.collections and bpy.data.objects:

    collection = bpy.data.collections.get(old_collection_name)

    collection.name = f"IfcBuildingStorey/{storey_name}"


    storey = bpy.data.objects[old_collection_name]

    storey.name = f"IfcBuildingStorey/{storey_name}"

else:

    raise ValueError("Couldn't edit storey name, default storey not found.")


parent_collection_name = f"IfcBuildingStorey/{storey_name}"

parent_collection = bpy.data.collections.get(parent_collection_name)

if not parent_collection:

    raise ValueError(f"Parent collection '{parent_collection_name}' not found.")


# Construct Ifc components

bpy.ops.object.select_all(action="DESELECT")

for obj in bpy.data.objects:

    if obj.type == "MESH":

        obj.select_set(True)


        bpy.ops.bim.assign_class(ifc_class="IfcBuildingElementProxy")


        # Unlink from any other collection (like 'IfcProject/My Project') before adding to storey

        for collection in obj.users_collection:

            collection.objects.unlink(obj)

        parent_collection.objects.link(obj)


        obj.select_set(False)  # Deselect the current object

This seems to work fine, but if I add the following lines to the Python file (saving the code as debug_renaming.py)


# Export the loaded model to IFC format

import sys


argv = sys.argv[sys.argv.index("--") + 1 :]

output_path = argv[0]

bpy.ops.export_ifc.bim(filepath=str(output_path), should_save_as=True, save_as_invoked=True)

and run from the command line


$ Blender -b -P debug_renaming.py -- cube_CLI.ifc

the cube will be linked to IfcBuildingStorey/My Storey instead of IfcBuildingStorey/Floor 1

I don't have any clue what is going on here, so help is much appreciated. If the renaming itself is done incorrectly I would love to hear the better way.

Using Blender 4.0.0, BlenderBIM 0.0.231104

A by Andrej730 on 20 Dec 2023 # +2 votes

Hi! Changing name of the story is much simpler, just change the name for the object:


obj = bpy.data.objects["IfcBuildingStorey/My Storey"]

obj.name = "test"

obj.name # 'IfcBuildingStorey/test'

P by pederlh on 20 Dec 2023, edited 20 Dec 2023 #

@Andrej730

Nice, this works in the script run from the UI. Still, the code


storey_name = "Floor 1"

if "IfcBuildingStorey/My Storey" in bpy.data.objects:

    storey = bpy.data.objects["IfcBuildingStorey/My Storey"]

    storey.name = storey_name

else:

    raise ValueError("Couldn't edit storey name, default storey not found.")


parent_collection_name = f"IfcBuildingStorey/{storey_name}"

parent_collection = bpy.data.collections.get(parent_collection_name)

if not parent_collection:

    raise ValueError(f"Parent collection '{parent_collection_name}' not found.")

raises the last ValueError


ValueError: Parent collection 'IfcBuildingStorey/Floor 1' not found.

when running the script from the CLI...

P by pederlh on 21 Dec 2023 #

Might be more suited for a Github issue: #4140