Hello fellow game developers,
I just imported a bunch of animations into Unity and some of them act very strange when I apply the character avatar. It’s only a handful of animations, and it appears that the problem is mostly only affecting the arms. We tried reexporting and importing the animations from maya, but it had no effect. The animations are baked and exported as FBX.
Any ideas what could be going wrong?
[15292-fucked+up+arms+2.png|15292]
Hello! I know this issue is old and has been resolved for the original poster, but I had this same issue and managed to figure out the cause.
Unity’s animation system applies constraints to the joints of an avatar, so that animations wont move the character in an unnatural way (for that character). I believe Unity does something approximately along the lines of clamping the f-curves to the allowed angles, and if you transgress the maximum angle for a joint too far, then it can end up getting clamped around to the minimum value, which results in a dislocated joint.
The fix for this is to apply proper constraints to your rig in your animation software, so that your joints work the same as those of the avatar in Unity. If you want your character to be able to bend some joint in an unnatural way, I believe you have to tweak the muscle settings in the avatar configuration.
The arms seem to be the general offender here, as it easily happens that you either roll the shoulder bone, or yaw the lower arm bone. Neither of these motions can happen in a normal human skeleton. It looks like the former is what was haunting the original poster, while I had problems with the latter.
Regards
“as it easily happens that you either roll the shoulder bone, or yaw the lower arm bone. Neither of these motions can happen in a normal human skeleton.”
May consider explaining this a bit simpler instead of using camera movement terminology, so others - non-animators can comprehend.
As an animator myself - I translate the explanations to mean - rotate the shoulder bone around it’s local axis = roll, and - I’m really not sure what yaw a lower arm bone means, since rotating a lower arm bone from its pivot point located at the joint of the parent bone is a proper animation process for FK/IK rigs. What type of translation/rotation does “yaw” represent?
Thanks for the clarification.