Creating a new coordinate system

[jegberink (jeroen egberink)]

hey!
You can see if this helps:

Defining a new coordinate system using markups plane node

The axes of a MarkupsPlane node are always orthogonal, even if the triangle of points used to define the plane is not a right triangle. If you have a MarkupsFiducial node with your three defining points, this function will produce a MarkupsPlane node def makePlaneMarkupFromFiducial(self, FNode, planeName): """Create MarkupsPlane using first three control points of the input fiducial node. """ if FNode.GetNumberOfControlPoints()<3: logging.warning('Not enough control points to…

Your point 1 to point 2 is your positive X-axis, which should correspond to the LR axis in Slicer.