# Rig Arm Twist – Maya

https://i.ytimg.com/vi/l_LgcFCOUoU/hqdefault.jpg

How to rig upper and lower arm twists, – 180 + 180 supported rotation.

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### 17 thoughts on “Rig Arm Twist – Maya”

• July 29, 2021 at 16:08

why the fuck u guys don't speak while making a tutorial, its so hard to watch in silence..

• July 29, 2021 at 16:08

Thank you for good information. I solved the problem. I have a question. Why use 4 joints each? If the limbs are short, can I shorten them to three? and Is this called quaternion? and..Shouldn't Nonroll JNT's upVextor be the opposite of the existing arm JNT?

• July 29, 2021 at 16:08

Edit: Nevermind – I found that this flipping thing with the Aim constraint is a limitation that comes with the underlying vector math.

follow up question: my arm chains only differ from yours in orientation (x – forward axis, y points down and z points in the negative negative z direction), I was able to correctly apply the (IK handle and the aim) constraints for elbow and shoulder, but when i twist my wrist past 90 degrees on my forward axis, the twist segments flip. if i change the up vector in the aim constraint's settings (- to +) the flipping still happens if I rotate the wrist -90 degrees. is this an unsolvable problem like gimbal locking? what's a good workaround for it?

• July 29, 2021 at 16:08

OMG, I circled around several tutorials for days (including an old one from Autodesk official) – this tutorial is the easiest to understand, is neatly done and make efficient minimal use of nodes. Thank you for this Alexandre.

• July 29, 2021 at 16:08

This does work for posing and slight rotation but when rotating the shoulder first and then bending the elbow, the shoulder starts to twist again but backward.

• July 29, 2021 at 16:08

This has been really helpful! Thanks! I'm curious, though. Why do you use Y and not X as your primary axis for orientation?

• July 29, 2021 at 16:08

Thanks for this! Helped me a lot!

Although I have a question, is it possible to have all the set-up (upperarm and lowerarm) either be full IK set-up or full aim constraint set-up?

If so, why did you choose a hybrid set-up?

• July 29, 2021 at 16:08

Thanks for this! Helped me a lot!
Although I have a question, is it possible to have all the set-up (upperarm and lowerarm) either be full IK set-up or full aim constraint set-up?
If so, why did you choose a hybrid set-up?

• July 29, 2021 at 16:08

Hi Alexandre,
Please email me at scotrreynolds@gmail.com
I need someone to animate a character for my website.
Thanks!

• July 29, 2021 at 16:08