To offset a polyline that is not in the same plane

I’m trying to make a shape with various polylines, can’t I offset it with polylines?
In particular, vertical lines show a lot of errors, so how can I solve this?

I was thinking that the image that I posted flows along the polyline.

offset help.gh (9.5 KB)
offset.3dm (95.6 KB)

@Joshua_Kennedy - can you help here?

Hi,

You can’t offset a line in the XY plane if it’s parallel to the planes normal like your vertical segments are. Behind the scenes Rhino is faking it by stitching the polyline segments back together that it could offset. This is giving you an answer that is not so useful. How do you expect Rhino to join the two green offset segments together?