Bug when evaluating constraints with plane

[Ultran1]

In file utils.py in function getElementRotation(obj,reverse=False) return value, axis, is affected with an array instead of a FreeCAD.Vector.

the function fit_plane_to_surface1(face.Surface) return an array :

plane_norm, _plane_pos, error = \
                    fit_plane_to_surface1(face.Surface)

then plane_norm is affected to axis.

axis = plane_norm

At the end of function call to FreeCAD.Rotation fail because axis is not a FreeCAD.Vector.

return FreeCAD.Rotation(FreeCAD.Vector(0,0,-1 if reverse else 1),axis)

I fixed this by using following code

axis = FreeCAD.Vector(plane_norm)

I expect the same problem will occur with this code:

            axis_fitted, _center, error = \
                    fit_rotation_axis_to_surface1(face.Surface)
            error_normalized = error / face.BoundBox.DiagonalLength
            if error_normalized < 10**-6: #then good rotation_axis fix
                    axis = axis_fitted

I fixed this by using following code

axis = FreeCAD.Vector(axis_fitted)

Here is the full part of the code that fails

else: #numerically approximating surface
            plane_norm, _plane_pos, error = \
                    fit_plane_to_surface1(face.Surface)
            error_normalized = error / face.BoundBox.DiagonalLength
            if error_normalized < 10**-6: #then good plane fit
                axis = plane_norm
            axis_fitted, _center, error = \
                    fit_rotation_axis_to_surface1(face.Surface)
            error_normalized = error / face.BoundBox.DiagonalLength
            if error_normalized < 10**-6: #then good rotation_axis fix
                    axis = axis_fitted

I use latest build FreeCAD-asm3-20180630-7e5b3323-f5dd9d4.glibc2.17-x86_64.AppImage on Debian Stretch 64bit host.

Bug successfully debugged with winpdb.

This is my first ever github bug report sorry for any mistakes.

[realthunder]

That's a very comprehensive bug report. Thanks for the help!