Offset Curves towards or away from the center

[rteuman]

Hello All,

I have sets of curves arranged in a somewhat circular way:

What I would like to do is to have these curves flipped in the direction facing away from the center, so I can offset them all outwards

Unfortunately it’s always the case that some of the curves are flipped inwards, while some outwards, like you see here when I plug them in to the offset component:

This is a simplified example, I have many more curves in different circular arrangements.

how can I flip all the curves inwards our outwards consistently? any help is appreciated!

here’s the internalised GH file:
flip outwards.gh (6.6 KB)

Thank you All!

[magicteddy]

Maths to the rescue here, check the determinant of three vectors (Z axis, line direction and vector from the center to the line).

flip outwards.gh (12.5 KB)

[Quan_Li]

flip outwards.gh (7.9 KB)
A curve has direction, and your curves have contradictory directions.
Unifying them is the solution. The plugin is called Flexibility.

[martinsiegrist]

@Quan_Li

A curve has direction

I don’t trust curve direction anymore since I’ve seen this:

Bug: Surface orientation / curve direction inconsistency - Serengeti (Rhino WIP) - McNeel Forum

[anon39580149]

You can offset line in the two directions then choose the line furthest from the center

flip outwards.gh (10.5 KB)

[rteuman]

Great methods, very helpful, thank so much all!