Flip curve is not flipping these open curves in the same direction?

Grasshopper
,
1

image
image2506Ă—1035 200 KB

I have a problem where this particular curve is not flipped correctly. I have many outlines and these should align to a single curve. It works for 500+ curves except for these two.
Flip curve - not flipping.gh (20.6 KB)
Version 8 SR25 (8.25.25308.13001, 2025-11-04)

2

Time to chastise these naughty curves.

Flip curve - now flipping.gh (28.6 KB)

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image1674Ă—872 101 KB

Flip curve - now flipping-worldX.gh (37.9 KB)

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image1761Ă—1249 200 KB

3

Thanks, I addressed this manually now. Bit odd that the Flip Curve component doesn’t work on this one particular case as I would assume it should. I wonder why that’s the case.

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image1800Ă—537 79.2 KB

Flip curves manual.gh (323.3 KB)

4

Didn’t understand what you meant by that (you did the same I did?), but glad you figured it out…

I think it’s completely normal for a gh curve offset that’s both positive and negative to have opposite directions—but maybe I’m wrong!

Best,
RC

5

Indeed, I used your method, but was wondering why the flip curve component didn’t do this for me (us).

That is indeed normal and it’s also normal for opposite surface edges to be in opposing directions. The question is why flip curve with a guide curve addresses all these curves correctly without the added extra logic. You’d think the guide curve option on the component is there to solve these particular cases…

6

I see—I {now} wonder the same thing.