Axis system is not handled when there are more nested subparts

[guoyin-zhao-ansys]

🔍 Before submitting the issue

• I have searched among the existing issues
• I am using a Python virtual environment

🐞 Description of the bug

Hello team,

When having nested subpart, the axis system for the last subpart seems to be not relative to its parent node but the global cs.

📝 Steps to reproduce

Simply run the project.py with following codes:

# ### Prepare the root part

root_part = p.create_root_part().commit()
root_part.create_body(name="Body.root").create_face(name="Face.root").set_vertices(
    [0, 0.1, 0.2, 0, 0.2, 0.2, 0.1, 0.2, 0.2]
).set_facets([0, 1, 2]).set_normals([0, 0, 1, 0, 0, 1, 0, 0, 1])
root_part.commit()

child_part1 = root_part.create_sub_part(name="SubPart.1").set_axis_system([5, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1]).commit()
child_part2 = child_part1.create_sub_part(name="SubPart.2").set_axis_system([5, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1]).commit()

child_part2.create_body(name="Body.1").create_face(name="Face.1").set_vertices(
    [0, 0.2, 0.4, 0, 0.4, 0.4, 0.2, 0.4, 0.4]
).set_facets([0, 1, 2]).set_normals([0, 0, 1, 0, 0, 1, 0, 0, 1])
child_part2.commit()
p.preview()

You will notice the body is at 5 mm to the origin instead of 10mm (subpart 1 is at 5mm to origin, subpart 2 is at 5mm to subpart 1 in x direction).

💻 Which operating system are you using?

Windows

📀 Which ANSYS version are you using?

SPEOS RPC 2025 R1

🐍 Which Python version are you using?

3.11

📦 Installed packages

ansys-api-speos        0.14.2
ansys-speos-core       0.3.0

[pluAtAnsys]

@StefanThoene please let me know your though regarding this, Should those be relative coordinate or global coordinate?

[StefanThoene]

mhm @pluAtAnsys i would say hey should ber relative if you move a sub part you are expecting the sub sub part to move as well

But that would then be on server side no?

[jomadec]

@StefanThoene @pluAtAnsys indeed the axis sytem of subpart is relative to parent part axis system,
https://github.com/ansys/ansys-api-speos/blob/63157fd226ca5f183dc539ced06d95c3c18c0819/src/ansys/api/speos/part/v1/part.proto#L17
so I think the issue comes from the preview method which consider all axis sytems are relative to global one it seems

            # Add mesh of bodies contained in sub-part
            subparts = find_all_subparts(root_part)
            for subpart in subparts:
                subpart_axis = subpart._part_instance.axis_system
                part_mesh_data = self.__extract_part_mesh_info(
                    part_data=subpart,
                    part_coordinate_info=subpart_axis,
                )
                if part_mesh_data is not None:
                    _preview_mesh = _preview_mesh.append_polydata(part_mesh_data)