Flip with guide curve fails

I have a bunch of ligns that I want to orient consistently using a guide curve.
In this case, it doesn’t work, although it looks like a very un-ambiguous case :

Flip with Guide fails.gh (31.0 KB)

This could be another way.

Flip with Guide fails_re.gh (35.0 KB)

Hi Kim,

It’s nice of you to propose a solution.
The issue is that it only works in this particular case, where my curves are kind of daisy-chained.

I did, I guess, a more bullet-proof version :

But the real issue is : what are the requirements for the guide curve to work as expected with the “Flip” component.
When possible, I like to use “high-level” tools rather than tedious workarounds.

Flip-component unfortunately does not work always correctly.
I made small c# component that does flipping according to the rule I use:

  1. find closest points btw curve and guideCurve
  2. find tangents at that points
  3. compare angle btw tangents, it angle>PI/2 flip curve

Flip Curves with Guide.gh (23.4 KB)

The guide curve isn’t considered locally at all, only the vector connecting its end points matters (and for closed curves, its orientation). What you want would require an additional input or a second component. It would be a useful thing to have though.

Hi David,

Even then, I would expect it to produce a consistent orientation in my case (see file from my initial post).

1 Like

I have had the same issue. My usual work around is to use the first curve in a series of curves as the guide curve. Recently i had a case, closed curves, where I actually had to run calcs twice, and then manually pick the best results, a few curves would simply not orient correctly, One thing I have not tried, come to think of it, is an explode/join sequence before alignment

Well, in my case, the curves don’t meet at their ends.
My approach using the guide curve’s “parameter at closest point” works well for me.