IfcOpenShell/src/bonsai/scripts/obj2ifc.py

# Bonsai - OpenBIM Blender Add-on
# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
#
# This file is part of Bonsai.
#
# Bonsai is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Bonsai is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.


# This can be packaged with `pyinstaller --onefile --hidden-import numpy --collect-all ifcopenshell --clean obj2ifc.py`
import argparse
import pywavefront  # pyright: ignore[reportMissingImports]
import ifcopenshell
import ifcopenshell.api
import ifcopenshell.api.aggregate
import ifcopenshell.api.context
import ifcopenshell.api.geometry
import ifcopenshell.api.project
import ifcopenshell.api.root
import ifcopenshell.api.spatial
import ifcopenshell.api.unit
import ifcopenshell.api.owner.settings
import ifcopenshell.guid
from pathlib import Path

import numpy as np


class Obj2Ifc:
    def __init__(self, paths, outfile):
        self.paths = paths
        self.outfile = outfile
        self.basename = Path(outfile).stem

    def execute(self, version="IFC4"):
        self.create_ifc_file(version)
        for path in self.paths:
            self.path = path
            self._execute()

    def _execute(self):

        self.scene = pywavefront.Wavefront(self.path, create_materials=True, collect_faces=True)
        for mesh in self.scene.mesh_list:

            faces = mesh.faces
            ifc_faces = np.zeros([len(faces)], dtype=object)
            for i, face in enumerate(faces):
                ifc_faces[i] = self.file.createIfcFace(
                    [
                        self.file.createIfcFaceOuterBound(
                            self.file.createIfcPolyLoop(
                                [
                                    self.file.createIfcCartesianPoint(self.get_coordinates(self.scene.vertices[index]))
                                    for index in face
                                ]
                            ),
                            True,
                        )
                    ]
                )
            representation = self.file.createIfcProductDefinitionShape(
                None,
                None,
                [
                    self.file.createIfcShapeRepresentation(
                        self.context,
                        "Body",
                        "Brep",
                        [self.file.createIfcFacetedBrep(self.file.createIfcClosedShell(ifc_faces.tolist()))],
                    )
                ],
            )
            product = self.file.create_entity(
                "IfcBuildingElementProxy",
                GlobalId=ifcopenshell.guid.new(),
                Name=mesh.name or self.basename,
                Representation=representation,
            )
            ifcopenshell.api.spatial.assign_container(self.file, products=[product], relating_structure=self.storey)
            product.ObjectPlacement = self.placement

        self.file.write(self.outfile)

    def get_coordinates(self, coordinates):
        # OBJ swaps Y and Z axis
        return [coordinates[0], -coordinates[2], coordinates[1]]

    def create_ifc_file(self, version):
        self.file = ifcopenshell.api.project.create_file(version=version)
        person = ifcopenshell.api.owner.add_person(self.file)
        person[0] = person.GivenName = None
        person.FamilyName = "user"
        org = ifcopenshell.api.owner.add_organisation(self.file)
        org[0] = None
        org.Name = "template"
        user = ifcopenshell.api.owner.add_person_and_organisation(self.file, person=person, organisation=org)
        application = ifcopenshell.api.owner.add_application(self.file)
        ifcopenshell.api.owner.settings.get_user = lambda ifc: user
        ifcopenshell.api.owner.settings.get_application = lambda ifc: application

        project = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcProject", name=self.basename)
        lengthunit = ifcopenshell.api.unit.add_si_unit(self.file, unit_type="LENGTHUNIT")
        ifcopenshell.api.unit.assign_unit(self.file, units=[lengthunit])
        model = ifcopenshell.api.context.add_context(self.file, context_type="Model")
        self.context = ifcopenshell.api.context.add_context(
            self.file,
            context_type="Model",
            context_identifier="Body",
            target_view="MODEL_VIEW",
            parent=model,
        )
        site = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcSite", name="My Site")
        building = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcBuilding", name="My Building")
        self.storey = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcBuildingStorey", name="My Storey")
        ifcopenshell.api.aggregate.assign_object(self.file, products=[site], relating_object=project)
        ifcopenshell.api.aggregate.assign_object(self.file, products=[building], relating_object=site)
        ifcopenshell.api.aggregate.assign_object(self.file, products=[self.storey], relating_object=building)

        ifcopenshell.api.geometry.edit_object_placement(self.file, product=site)
        ifcopenshell.api.geometry.edit_object_placement(self.file, product=building)
        ifcopenshell.api.geometry.edit_object_placement(self.file, product=self.storey)

        self.origin = self.file.createIfcAxis2Placement3D(
            self.file.createIfcCartesianPoint((0.0, 0.0, 0.0)),
            self.file.createIfcDirection((0.0, 0.0, 1.0)),
            self.file.createIfcDirection((1.0, 0.0, 0.0)),
        )
        self.placement = self.file.createIfcLocalPlacement(self.storey.ObjectPlacement, self.origin)
        self.history = ifcopenshell.api.owner.create_owner_history(self.file)


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Converts an OBJ to an IFC")
    parser.add_argument("obj", type=str, nargs="+", help="One or more OBJ files")
    parser.add_argument("-o", "--output", type=str, help="The output file to save the patched IFC", default="out.ifc")
    args = parser.parse_args()

    obj2ifc = Obj2Ifc(args.obj, args.output)
    obj2ifc.execute()