Twist Correction on Mixamo arm issue.

I have a Two Bone Ik on the arm of my Mixamo character and it works just fine. I added a Twist Correction component and now when I Play the scene the arm moves to a different start position and moves in the opposite direction of the ik target. If I set the Twist Correction to 0 the arm goes back to the right position and moves correctly with the ik target. Is this an issue with Mixamo rigs as the arm and forearm have the y axis running along the arm but the hand has -ve x running along the hand.
Is there a way to get Twist Correction working with a Mixamo rig?

My settings for the IK Constraint and the Twist Correction
6413079--716448--ikarm1.png
The arm in the correct positon when Twist Correction weight set to 0
6413079--716445--ikarm2.png
The arm drops when the Twist Correction weight is moved to 1 and no longer tracks the IK target correctly.
6413079--716442--ikarm3.png

Hey, as far as I can tell from the images it works as intended. Please have a look at the samples how the twist correction is intended to be used. Or the illustration in the documentation. Twist correction should generally be used on bones specifically authored for this. Usually these are leaf bones to your upper or lower arm bones. As far as I can tell the rig you are using does not have these.

So you are saying that adding a twist will move the IK away from its target? How can that be expected behaviour, it makes it impossible to use IK with Twist.

To use twist correction on an arm you need to create a bone hierarchy that supports twist correction. This setup includes the bones for the arm (to be controlled by the two bone IK) and leaf bones to the arm that drive the skinning (to be controlled by the twist correction). In your case you are applying both to only the arm. So first two bone IK is applied, which ensures you reach for your target. But after this twist correction is executed which changes the pose again.6416646--717006--upload_2020-10-14_13-3-33.png

Might be nice then if the docs and the examples reflected this requirement or at least mentioned it is not to be used on bones forming an IK Chain.

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