Unite function with Surface Body

[martin-woodplc]

Dear Developers,

I'm trying to generate an eccentric conical shape. the only way I found is using a combination of create_surface and create_body_from_loft_profile function to obtain the 3 surfaces body that will form my solid. When assembling these 3 surfaces in SpaceClaim using the Combine button, it works well, ending up with the desired solid body.

However when using the unite function from the API I got the following error:
"ValueError: Boolean operation of type 'unite' failed: union operation failed."

Is this normal behavior? Is there a different way to "stitch" multiple surface body into a solid body?

The code:

#1st Surface - Start
plane = Plane(Point3D([0,0,0]), direction_x=Vector3D([1,0,0]), direction_y=Vector3D([0,1,0]))
sketch = Sketch(plane)
sketch.circle(Point2D([0, 0]), 0.1 * UNITS.m)
surface1 = design.create_surface("surface1",sketch)

#2nd Surface - End
plane = Plane(Point3D([0,0,0.3]), direction_x=Vector3D([1,0,0]), direction_y=Vector3D([0,1,0]))
sketch = Sketch(plane)
sketch.circle(Point2D([0.05, 0]), 0.15 * UNITS.m)
surface2 = design.create_surface("surface2",sketch)

#3rd Surface - Loft
circleStart = Circle(Point3D([0,0,0]), 0.1 ,reference=Vector3D([1,0,0]),axis=Vector3D([0,0,1])).trim(Interval(0, 2 * np.pi))
circleEnd = Circle(Point3D([0.05,0,0.3]), 0.15 ,reference=Vector3D([1,0,0]),axis=Vector3D([0,0,1])).trim(Interval(0, 2 * np.pi))
surface3 = design.create_body_from_loft_profile("surface3", [[circleStart],[circleEnd]])

#Unite all surfaces
surface3.unite([surface2,surface1]) #Error here

Thanks in advance.

Martin

[RobPasMue]

Hi @martin-woodplc - thanks for opening this discussion!

Let's figure out some extra details from your request:

1. Which Ansys SpaceClaim version are you using?
2. Which ansys-geometry-core version are you using?
3. What is your Python version and what is your dev environment (i.e. run pip list and post the output - packages installed and specific verrsions)?

Pinging @jonahrb @b-matteo for visibility

[martin-woodplc]

Hi @RobPasMue,

Thanks for the quick reply. Here are the info:

• I'm using version Ansys SpaceClaim 24r2 (I tested also on Discovery 24r2 with same error)
• With ansys-geometry-core 0.8.1
• Python 3.11.4 with the following package:

Package                               Version
------------------------------------- -----------
aiohappyeyeballs                      2.4.4
aiohttp                               3.11.11
aiosignal                             1.3.2
ansys-api-dbu                         0.3.8
ansys-api-geometry                    0.4.27
ansys-api-mechanical                  0.1.2
ansys-api-platform-instancemanagement 1.1.0
ansys-geometry-core                   0.8.1
ansys-mechanical-core                 0.11.8
ansys-mechanical-env                  0.1.8
ansys-platform-instancemanagement     1.1.2
ansys-pythonnet                       3.1.0rc3
ansys-tools-path                      0.7.1
ansys-tools-visualization-interface   0.8.1
appdirs                               1.4.4
attrs                                 24.2.0
beartype                              0.19.0
certifi                               2024.12.14
cffi                                  1.17.1
charset-normalizer                    3.4.1
click                                 8.1.8
clr-loader                            0.2.6
colorama                              0.4.6
contourpy                             1.3.1
cycler                                0.12.1
flexcache                             0.3
flexparser                            0.4
fonttools                             4.55.4
frozenlist                            1.5.0
grpcio                                1.67.1
grpcio-health-checking                1.67.1
idna                                  3.10
importlib_metadata                    8.5.0
kiwisolver                            1.4.8
matplotlib                            3.10.0
more-itertools                        10.6.0
msgpack                               1.1.0
multidict                             6.1.0
numpy                                 2.2.2
packaging                             24.2
pillow                                11.1.0
Pint                                  0.24.4
pip                                   24.2
platformdirs                          4.3.6
pooch                                 1.8.2
propcache                             0.2.1
protobuf                              5.29.3
psutil                                6.0.0
pycparser                             2.22
pyparsing                             3.2.1
python-dateutil                       2.9.0.post0
pyvista                               0.44.2
requests                              2.32.3
scipy                                 1.15.1
scooby                                0.10.0
semver                                3.0.2
setuptools                            65.5.0
six                                   1.17.0
tqdm                                  4.66.5
trame                                 3.7.6
trame-client                          3.5.2
trame-server                          3.3.0
trame-vtk                             2.8.14
trame-vuetify                         2.8.0
typing_extensions                     4.12.2
urllib3                               2.3.0
vtk                                   9.3.1
websockets                            14.2
wslink                                2.2.2
yarl                                  1.18.3
zipp                                  3.20.2

[skyrungit]

@RobPasMue Is there an update or work around on this issue? To make a truncated cone.

[RobPasMue]

Hi @skyrungit, @martin-woodplc - I think this discussion probably fell through the cracks on my side. Sorry for the late response!

Starting on 24R2, it would be easy to follow this approach:

https://geometry.docs.pyansys.com/version/stable/examples/03_modeling/revolving.html

If you draw a trapezoidal sketch representing a vertical cut of your truncated cone, and revolve the sketch along the central axis of your cone, you should be able to get what you are looking for! =)

Let me know how it goes!

[RobPasMue]

Maybe using the create_body_from_loft_profile function is a good option. We are still working on a demo script for this but you can see a test here:

pyansys-geometry/tests/integration/test_design.py

Lines 2895 to 2916 in ea2df5d

	def test_create_body_from_loft_profile(modeler: Modeler):
	"""Test the ``create_body_from_loft_profile()`` method to create a vase
	shape.
	"""
	design_sketch = modeler.create_design("loftprofile")
	profile1 = Circle(origin=[0, 0, 0], radius=8).trim(Interval(0, 2 * np.pi))
	profile2 = Circle(origin=[0, 0, 10], radius=10).trim(Interval(0, 2 * np.pi))
	profile3 = Circle(origin=[0, 0, 20], radius=5).trim(Interval(0, 2 * np.pi))
	# Call the method
	result = design_sketch.create_body_from_loft_profile(
	"vase", [[profile1], [profile2], [profile3]], False, False
	)
	# Assert that the resulting body has only one face.
	assert len(result.faces) == 1
	# check volume of body
	# expected is 0 since it's not a closed surface
	assert result.volume.m == 0

[skyrungit]

The point here is that we need below 2 function.

1. “Blend” button in SpaceClaim, which returns a solid body when we select 2 parallel faces. (“Design”->”Edit”->”Blend” at the ribbon tool bar)
2. unite() funcion to work not only with solid body, but also with surface body.

[RobPasMue]

Maybe @jacobrkerstetter @b-matteo @smereu and @jonahrb can help out on this one.

[jacobrkerstetter]

@skyrungit Try the method that was just added in #2282 - combine_merge - for uniting surface bodies

[RobPasMue]

Method is not available yet (only on the main branch) but as soon as a version is out he will be able to give it a try easily. In the meantime @skyrungit feel free to checkout the main branch of the pyansys-geometry repository to try it out