Vellum hair to collide with eachother but not with itself

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Hello!

Given a set of vellum hairs, I want them to collide with eachother but not with themselves, meaning I don't want the points of a hair strand (curve) colliding with other points of that same strand but doing so with other hair strands.
Turning "Self Collisions" makes so that no point collides with any other point of any strand, so that wouldn't work for this case. And things like i@disableself or i@disableexternal can't achieve this level of granularity. Same goes for collision groups.

The reason I am behind this is that when dynamically modifying @restlenght, self collisions make the sim behave unstably (and rightfully so, since in contractions @restlength is basically telling the points of the strand to get closer than "physically" possible according to their specified thickness).

I was wondering if there is a hidden toggle I am missing to get this or a thread that goes through this topic already before I jump inside the solver to tweak it. I feel like this is a pretty handy feature and not so rare or farfetched.


Thanks!
Edited by Cicuta - March 28, 2025 16:53:02
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Cicuta
... can't achieve this level of granularity. Same goes for collision groups.
why not?
you can make all points have s@collisiongroup name unique to that hair and also s@collisionignore the same name
Tomas Slancik
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You are absolutely right! I had a typo and then assumed it was only usable for external collisions. Sorry for the confusion and thread!

Thanks!
Edited by Cicuta - March 29, 2025 04:28:47
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check Fabio hair system, I did a node that let you control that based on length of the curve, since was needed to control the root, you can copy paste that vop into your network
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