Keeping polyline direction constant

[brt1]

tweaking the length and angle of this parallelogram (the two sliders on the left) makes the direction of the polyline flip so the offset gives a wrong result.
any ideas for a simple solution to keep the curve direction constant?

thanks in advance
roberto

04.gh (17.6 KB)

[inno]

if the image in your picture is what you are looking for, then I’d suggest to input the plane on which you want to offset to happen, in the P input of the Offset components:

04_Re.gh (16.3 KB)

[brt1]

thanks!!