Maybe when you choose "flat", I can default to the world z axis direction, but show a button underneath it that says "Set flat dir", and if you push it let you pick 2 points to define the direction.

- Michael

Why not automatic get helix both end points?

Hi Johny - that would be difficult because the default isn't "flat" mode, it is the freeform twist mode which does not need any direction information.

So that would feel a little odd if I forced you to pick 2 points every time you did sweep, but then did not use that information by default.

- Michael

Ah, I think you're right Michael ;)
Sorry, I forgot that 3dm file format not save start and end point of created helix information.

And I agree with a button option for select start and end point of direction if we select Flat mode.