Character Hands Stuck During Animation

Question

I'm having a problem with some of my animations. My character is an ape and I designed 19 animations. For two of them, sometimes my ape's hands get "stuck" in place, and the rest of the mesh contorts and distorts as it plays the animation. See screenshot - the left image is when it distorts, the right is when it plays correctly. Strangely, I'm able to fix this in Blender by switching back to certain other animations (not just any other animation - it only works with a few). Then when I switch back, the problem animations run correctly and the hands are no longer stuck in place. The big problem is - when I export my model and armature as FBX and import into Unity, those animations always play incorrectly with the hands stuck in place. I think this has to do with the IK bones (inverse kinematics) I applied to the hands at a certain point. But it's strange because this problem only applies to two animations out of 19. Any advice on how to fix this would be greatly appreciated. The file is too large to upload but I'll gladly send it via email ([email protected]). Thanks!

Answer 1

You need to check 2 things: The keyframes of your IK controller bone, and the Influence value of the IK bone.

• First enable the Only Include Channels Relating to Selected Objects button (arrow icon). It will allow you, in the Dopesheet, to only display the keyframes of the selected bones.
• Now select the controller bone and switch from an action to another, you'll see that sometimes the controller doesn't have any keyframe at the beginning of the action, which means that, until the next keyframe, the controller will keep the position that it got at the end of the previous action, is it what you want?
• Also, you'll see that for some animations you have keyframed the Influence value of the Ik bone, so for some animations it will be at 0 and the IK won't work anymore, and will remain off if you switch to another action that has no keyframe for this value, again if there is no new value keyframed at the beginning only the previous one from the previous animation will be taken into account. Again, is it what you want?

So to fix both these 2 problems you may need to create some keyframes at the beginning of the action: Keyframes for your controller and/or IK Influence value.