We have hand rotation controlled by a motion controller. In order to improve the deformation of the character we want to remove\adjust the roll from the input rotation, and apply the modified rotation to the wrist bone using a Transform (modify) bone in the AnimBlueprint. When removing the roll, certain rotation values cause the target bone to flip.
Is there any suggestions\tutorials\examples of how to setup this type of control on a character?
Any help is highly appreciated.
Thanks!
My guess is you’re not using quaternion math to calculate the roll delta. If you’re just using rotators, you could get wonky results depending on the range of motion. This entry talks more about that approach:
Thank you! So If I understand the link, it could be done, but the tools currently inside in an AnimBlueprint are not enough.
From the link:
We did however expose several maths
functions which convert to quaternion
under the covers (e.g. ‘Combine
Rotators’ and ‘Negate Rotator’ nodes).
You can also use a Transform which
stores the rotation as a quaternion
internally.
I would see if “Combine Rotators” does what you need, otherwise you can try using Transform operations (eg. get the current transform, concatenate the delta rotation onto that transform, then apply that new transform to the object…I think you can do that in blueprints?). I can try to provide a sample screenshot later if you don’t sort it out.
I have tried “Combine Rotators” and also transform operations, but both do not output the desired results. I am having trouble figuring out how to properly get the delta roll which I can then use to remove it from the source input. It falls apart for me when the pitch gimbal locks.
This Link is talking about very similar problem but no solution is mentioned.
Unfortunately, I’m not familiar enough w/ Blueprints to help you out further 
It Sounds like maybe you don’t have the tools exposed there to do what you want. I’ve seen more than a few posts about Gimbal Lock here on the forums. Not sure why quaternion operations aren’t available in Blueprints…or if not that, other wrappers to perform these operations.