Sweep1 fail?

Hi all,

Attached is a student file with a rail and a profile. The profile is just a circle I put in there to test, the original was something else - but it seems that no matter what the profile is, the rail seems to be preventing it from sweeping properly. It goes a short distance but the wrong way. Rhino Sweep1 works with no problem in this case. I know the rail curve is not great, but I couldn't find anything really structurally wrong with it, shouldn't this work? Rebuilding the rail curve didn't help either...

Thanks,

--Mitch

Attachments:

GHSweepTest.3dm, 53 KB
GHSweepTest.ghx, 19 KB

Replies to This Discussion

Permalink Reply by David Wood on June 8, 2010 at 8:04am

Quick guess Mitch, try flipping the direction of the curve before sweeping the profile.

Permalink Reply by Juan_P on June 8, 2010 at 8:58am

hey david.
I tryied his definition..and rotated the curve..and it works that way...can you please explain why it works this way??

thanks

Permalink Reply by David Wood on June 8, 2010 at 9:12am

Juan,

Like surfaces, and other things in Rhino, curves have a direction. You can see the direction of the curve in the Rhino window by using the 'Analyze Direction' button, which is just under the rotate button in the main tools palette. This natural direction of the rail curve needs to be going in the same direction as you want the sweep profile to travel, otherwise the profile curve wants to shoot off the end of the rail!

So, if you've rotated something in the file, then you've probably managed to make the 'directions' of the objects line up and sweep successfully - i guess.

Simply by manually flipping the rail curve in rhino, or adding a flip component to the gh file sorts the problem.

D.

Permalink Reply by Juan_P on June 8, 2010 at 9:28am

David.
thank you for that fine and clear explanation..

Permalink Reply by Mitch Heynick on June 8, 2010 at 9:06am