Unify curves' directions in Python

Hi all,

I need to unify the directions of a set of curves for a python code.

In order to achieve this in grasshopper, I was usually taking one item from the curves list and using it as a guide curve for the 'Flip Curve' component.

Now I'm trying to do this in python, but it doesn't seem to work properly, sometimes flipping curves that were already in the same direction with the first curve.

This is the code I tried:

import rhinoscriptsyntax as rs

def matchCrv(crv2,crv1):
flip = False
if rs.CurveDirectionsMatch(crv2, crv1):
print 'match'
else:
x = rs.ReverseCurve(crv2)
flip = True
print x
return flip

F = []

for i in C:
tmpflip = matchCrv(i,C[0])
F.append(tmpflip)

and these are the logs from the 'Flip Curve' and from the code:

*all the curves are closed planar polylines

Only curve #5 had different direction from other curves, but in python curve #3 was flipped too.

Is there anything I'm missing here?

Thanks,

Michael

Attachments:

flip_curves.gh, 7 KB

Replies to This Discussion

Permalink Reply by Michael Weizmann on April 13, 2016 at 2:50pm

Obviously, it does work if I call 'Flip Curve' component inside python, but I was hoping to avoid importing ghpythonlib:

from ghpythonlib import components as ghcomp
F = ghcomp.FlipCurve(C,C[0])[1]

print F

----------------------------------

[False, False, False, False, False, True]

Permalink Reply by Michael Weizmann on April 13, 2016 at 11:55pm

Works like magic

Thanks a lot Marcus!

Permalink Reply by Michael Weizmann on April 14, 2016 at 6:36am

I think that this image can describe the poor situation: