I have a curve where I used the parallel transport algorithm to transport the normal along the curve and then I use this curve as a follow curve for a bone chain. My question now is how can I setup up the twist along the bone chain and also make it twist beyond 180 degrees without flipping? (see attached file below) any guidance and examples will be greatly appreciated. Thanks.

https://www.sidefx.com/tutorials/parallel-transport/ [www.sidefx.com] maybe this can help?

@Dexo thanks, I just ran through the video but I already have the algorithm figured out and I already have correct coordinate frames running along the curve. What I want now is how to use this to drive the twist axis of the bones (which are driven by the follow curve CHOP) and get a distributed twist that goes beyond the -180-180 quaternion limit.

Hi,

have you tried matrix rotations instead? It seems to work quite well, if you rotate the normals around the tangent.

Aizatulin
Hi,

have you tried matrix rotations instead? It seems to work quite well, if you rotate the normals around the tangent.

Thanks for setup @Aizatulin. Good stuff, but it still flips out at 180. I'm wondering if using the bones rest angles is the way to go and avoid Houdini's stupid (stupid to me)curve normals feature on the inverse kin CHOP? don't know man. I just have to try some shit now. Thanks though bro.

miccetro

Aizatulin
Hi,

have you tried matrix rotations instead? It seems to work quite well, if you rotate the normals around the tangent.

Thanks for setup @Aizatulin. Good stuff, but it still flips out at 180. I'm wondering if using the bones rest angles is the way to go and avoid Houdini's stupid (stupid to me)curve normals feature on the inverse kin CHOP? don't know man. I just have to try some shit now. Thanks though bro.

@Aizatulin this solution was actually quite stable. I'm still on this but just lettin' you know this is very usable for me. Not sure if I can come up with another solution but thanks again.

Sure man nice that is working, but I don't have another idea at the moment aswell.