What is ifcopenshell.api.run ... "edit_object

B by bernd on 14 Apr 2023, edited 14 Apr 2023 #

a minimalisic spatial structure is added to a ifcfile as follows ... from https://github.com/IfcOpenShell/IfcOpenShell/blob/v0.7.0/src/blenderbim/scripts/obj2ifc.py#L116-L127

        site = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcSite", name="My Site")

        building = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcBuilding", name="My Building")

        self.storey = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcBuildingStorey", name="My Storey" )


        ifcopenshell.api.run("aggregate.assign_object", self.file, product=site, relating_object=project)

        ifcopenshell.api.run("aggregate.assign_object", self.file, product=building, relating_object=site)

        ifcopenshell.api.run("aggregate.assign_object", self.file, product=self.storey, relating_object=building)



        ifcopenshell.api.run("geometry.edit_object_placement", self.file, product=site)

        ifcopenshell.api.run("geometry.edit_object_placement", self.file, product=building)

        ifcopenshell.api.run("geometry.edit_object_placement", self.file, product=self.storey)

What does the lines ifcopenshell.api.run("geometry.edit_object_placement", self.file, product=site) exactly do?

C by Coen on 14 Apr 2023 #

What does the lines ifcopenshell.api.run("geometry.edit_object_placement", self.file, product=site) exactly do?

I think it allows for a transformation of an object?

In this code snippet it's used to make an array of beams


for i in range(0, length_total_x, center_to_center_distance):



            matrix_x = numpy.array(

                            (

                                (1.0, 0.0, 0.0, i),

                                (1.0, 1.0, 1.0, profile_offset_y),

                                (0.0, 0.0, 0.0, 0.0),

                                (0.0, 0.0, 0.0, 1.0),

                            )

                        )



            matrix_x = numpy.array(matrix_x)


            occurrence =  run("root.create_entity", model, ifc_class="IfcBeam", name=beam_name)

            representation = run("geometry.add_profile_representation", model, context=representations["body"], profile=profile, depth=beam_length_y) 



            run("geometry.edit_object_placement",model, product=occurrence, matrix=matrix_x) 

            run("spatial.assign_container", model, relating_structure=storey, product=occurrence)

            run("geometry.assign_representation", model, product=occurrence, representation=representation)

            run("style.assign_representation_styles", model, shape_representation=representation, styles=[style])

B by bernd on 14 Apr 2023 #

But why is it needed for Spatial structure objects without representation?

M by Moult on 14 Apr 2023 # +2 votes

@bernd just because they do not have a representation doesn't mean that it shouldn't have a placement. For example, the placement of a building storey uses its Z ordinate to specify the elevation. Similarly, a placement at the building or site level makes it easy to shift the entire building / site relative to it.

OSArch Community

What is ifcopenshell.api.run ... "edit_object_placement" useful for?