plane_to_rhino bug: add missing y-axis vector argument

[jwwang0-0]

What type of change is this?

• Bug fix in a backwards-compatible manner.
• New feature in a backwards-compatible manner.
• Breaking change: bug fix or new feature that involve incompatible API changes.
• Other (e.g. doc update, configuration, etc)

This PR fixes an issue where plane_to_rhino() constructed a Rhino.Geometry.Plane with only two arguments (origin point + x-axis). Rhino’s Plane constructor requires three arguments:

• origin point
• x-axis
• y-axis

The current code will direct to another constructor :

public Plane(
[Point3d ] origin
[Vector3d ] normal
)

And will cause troubles like

Checklist

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• I added a line to the CHANGELOG.md file in the Unreleased section under the most fitting heading (e.g. Added, Changed, Removed).
• I ran all tests on my computer and it's all green (i.e. invoke test).
• I ran lint on my computer and there are no errors (i.e. invoke lint).
• I added new functions/classes and made them available on a second-level import, e.g. compas.datastructures.Mesh.
• I have added tests that prove my fix is effective or that my feature works.
• I have added necessary documentation (if appropriate)

[tomvanmele]

a COMPAS plane only has a point and a normal (it is not a frame). index 0 will return the base point, and index 1, the normal.

accessing index 2 on a plane object will raise a KeyError.

[tomvanmele]

the redirection to the constructor that uses a point and a normal is correct. i think the functionality you are looking for is frame_to_rhino...

[jwwang0-0]

Oh, thank you for the explanation! I'm wrong. That makes sense. I think it would be better to include a data type check in the code to verify whether the input is a compas_plane or a compas_frame. As it stands, it’s a bit confusing, especially since in Rhino plane is defined in a way that’s more similar to a compas_frame.

[Copilot]

Pull request overview

This PR attempts to fix a bug in the plane_to_rhino() function by adding a third argument (y-axis vector) to the Rhino.Geometry.Plane constructor. The PR author correctly identifies that the Rhino.Geometry.Plane constructor with 3 arguments requires (origin, xaxis, yaxis) rather than using the 2-argument constructor (origin, normal).

However, the proposed fix is critically flawed and will cause a runtime error. COMPAS Plane objects only contain 2 elements: a point and a normal vector. The fix attempts to access plane[2], which doesn't exist and will raise a KeyError. The correct approach requires converting the COMPAS Plane to a Frame first using Frame.from_plane(), which computes the xaxis and yaxis from the normal, then passing those to the Rhino constructor as demonstrated in the existing frame_to_rhino_plane() function.

Key Issues

• The code will crash with a KeyError when trying to access plane[2]
• COMPAS Plane has __len__() = 2 and __getitem__() only supports indices 0 (point) and 1 (normal)
• The fix needs to compute xaxis/yaxis from the plane's normal using Frame.from_plane()

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[gonzalocasas]

Should we close this? Or is anyone planning to add the type check as a fix instead?

[tomvanmele]

I don't think there is anything to be fixed... it is true that the plane/frame thing in relation to rhino is confusing, but that is because rhino doesn't distinguish between the two.

i think it can be closed...