Bone Constraints - Pin

The point of this restriction is to be able to fix Rig's bone in world space, regardless of how the character moves as a whole. For example, if you move a character along a curved curve, then the legs slip because the character turns. And the IK constraints move with the character along a curved trajectory. With this restriction, it will be possible to use an animation loop without having to put keys on long animations. Well, it can be useful in many other places.