IfcOpenShell - building a tree and select by ray

I followed the idea in the docs about building a geometry tree and selecting by ray.

However for some reason the following code doesn't work:


import multiprocessing

import ifcopenshell

import ifcopenshell.geom

import logging

logging.getLogger().setLevel(logging.DEBUG)

ifc_file = ifcopenshell.open(r'tests\models\cube.ifc')

tree = ifcopenshell.geom.tree()

settings = ifcopenshell.geom.settings()

settings.logger = logging.getLogger()

iterator = ifcopenshell.geom.iterator(settings, ifc_file, multiprocessing.cpu_count())

i = 0

origin = (0., 0., 0.)

direction = (1., 0., 0.)

length = 50.

if iterator.initialize():

    while True:

        # Use triangulation to build a BVH tree

        tree.add_element(iterator.get())

        i += 1

        if not iterator.next():

            break

    logging.debug(f"{i} elements added to tree.")    

    results = tree.select_ray(origin, direction, length)

    print(f"Number of results: {len(results)}")

    for result in results:

        print(ifc_file.by_id(result.instance.id()))

There aren't any errors, my results is just empty.

However, when I don't use the iterator, like this:


import multiprocessing

import ifcopenshell

import ifcopenshell.geom

import logging

logging.getLogger().setLevel(logging.DEBUG)

ifc_file = ifcopenshell.open(r'tests\models\cube.ifc')

tree = ifcopenshell.geom.tree()

settings = ifcopenshell.geom.settings()

settings.logger = logging.getLogger()

iterator = ifcopenshell.geom.iterator(settings, ifc_file, multiprocessing.cpu_count())

i = 0

origin = (0., 0., 0.)

direction = (1., 0., 0.)

length = 50.

mytree = ifcopenshell.geom.tree(ifc_file, settings)

results = mytree.select_ray(origin, direction, length)

for result in results:

    print(ifc_file.by_id(result.instance.id()))

Then I get the results I expect. So I'm pretty sure I'm using the iterator wrong.

Any advice much appreciated, thanks.