Offsetting and overriding curve indices?

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1

I know that you can offset index values of any curve using Offset Point in Curve node. However, I also want those changes to override the curve’s original “index” values and not creating a new one with Store Named Attribute node, is there a way to achieve this?

2

Well, to be clear, it’s not offsetting value, it allows to access index that are further down the list.

The index relate to how the data is stored on disk, point index 1 of curve index 1 is basically the first point of the first curve as it’s stored in memory. Therefore you can’t write a new index, if you really want to do that you need to shuffle the data and it’s not simple :
Basically if you want to swap curves 1 and 2 you need to create two new curves and let the first one get the same amount of point and position that the curve 2 and do the same with the second.

I 'm not sure there is a nodegroup somewhere that does that, if you reaaaallllly want to do that I can give some pointers about how to do that, but it’s pretty painful and I recommend you to find another way to get to the result you’re after if possible !

Good luck !

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3

Yeah, that’s pretty much what I’ve assumed so far, therefore I decided to just stick with a basic workaround where I just create a node group that accepts the current index, an offset value and a total point count that in conjunction with a Math Addition node and a Math Floored Modulo node successfully emulate index offsetting. Thank you for the response, nonetheless.

4

edit: nevermind, didn’t understand question.

Blender 4.1 has a new node called Sort Elements. I haven’t tried it, but it seems to do what you’re looking for:

The Sort Elements node rearranges geometry elements by changing their indices.`

https://docs.blender.org/manual/en/4.1/modeling/geometry_nodes/geometry/operations/sort_elements.html

5

But not for curve points, apparently - the error says “Domain and geometry type combination is unsupported”. (Splines in a curve through are a different matter.)
Which, I suppose, makes sense: curves are directional - the order of points seem very important.

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6

Blender 4.0’s Points to Curve has a weight input which acts exactly like 4.1’s Sort Element’s. So for curves you can convert to points and back to curve adding weight and that would sort it.

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