Question about Sweep1 and Sweep 2 use

Rhino Rhino for Windows
1

Hello,

I am trying to create a plank (of an ancient ship) in 3D. I have two lines available which follow the general form of the ship and I have a couple of cross-sections of the plank available.
When I use the Sweep1 or Sweep2 command to construct the plank I get all kind of deformations which I don’t understand (see attached image and the plank.3dm file).
Could anyone explain why these deformations occur and how I can solve them?

plank.3dm (7.9 MB)

Deformations
Deformations.jpg1352×746 259 KB

Kind regards,
Sander Vos

2

Hi Sander - when you use closed section curves, the direction must match, curve to curve - in your example one section curve is flipped - use the Flip command line option and click on the white direction arrow on the one odd-ball and it should all work.
I see the last section curve is also an odd-ball in that it hits the rail curve at a different corner of the rectangle than the others.
image

plank_PG.3dm (100.4 KB)
-Pascal