Rig Arm Twist - Maya

[@DoraKage]

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.

[@trevital1422]

Great stuff Alexandre, Hope to see more from you.

[@deuksooseo]

Best tutorial of Twist Thanks

[@alphaillusion4541]

You're the man, man! Very very helpful. THANKS!!!

[@RobertHoefig]

My arms twisting fine! Thanks! :)

[@dominikh8835]

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.

[@jimmitchell4698]

1:22 is supposed to be ctrl + left click.

[@yeonpark6772]

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?

[@bentraje]

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?

[@RoBaer90]

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

[@1V4NP3R3Z]

This doesn't work once the shoulder joint rotate Y goes past 180

[@DoraKage]

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?

[@alexandrecoirier1048]

Try to set aimConstraint like : aim 1 0 0 up 0 1 0 world 0 1 0

[@andreasgeorgiou1901]

does this method solve the 180 flip you get with most forearm setups?

[@alexandrecoirier1048]

No, with this method "twists" flip up to 180 and less than -180

[@arafatrishad5628]

my twist is not working when i getAttr elbow.translateY its return 0 if i put translateX then give value.i work with that value.above all i do all the same you do. please help me

[@alexandrecoirier1048]

It's beacause I work in Y up and you probably in X up, each time I set/connect a rotate or a translate on Y, you have to set/connect it on X. Set the rotate order xyz or xzy when I set yzx. For the aimconstraint, try to set it like this : aim vector : 1,0,0 up vector : 0,1,0 or 0,0,1 w up vector : 0,1,0 or 0,0,1

[@muheshhosee3618]

how to connect fk

[@bentraje]

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?