Rotation in plane created by API : is it normal?

Support Feature requests
1

If a markups plane is created using the API, and its normal and origin are set to those of another plane interactively placed in a rotated 3D view, the plane created by API has an extra rotation.

interactivePlane = getNode("P")

# New plane on interactive plane : there is an additional rotation
apiPlane = slicer.mrmlScene.AddNewNodeByClass("vtkMRMLMarkupsPlaneNode")
apiPlane.AddControlPointWorld(interactivePlane.GetOriginWorld())
apiPlane.SetNormalWorld(interactivePlane.GetNormalWorld())

# New plane on api plane : there is no additional rotation
apiPlane2 = slicer.mrmlScene.AddNewNodeByClass("vtkMRMLMarkupsPlaneNode")
apiPlane2.AddControlPointWorld(apiPlane.GetOriginWorld())
apiPlane2.SetNormalWorld(apiPlane.GetNormalWorld())

rotated_api_planes

Is this to be expected? If so, how should it be handled in user code to cancel this rotation?

Thank you.

2

Yes, this is the expected behavior, because normal direction does not specify the orientation of a rectangle in 3D. You need to specify direction of all the axes if you care about the rotation around the normal vector.