I am trying to deal with Blender's IK solving system (though maybe I don't need it at all?). I need to animate torus into a smile-like figure (upside- and downside-"smile" animation will be for the same armature.
Maybe it would be good to use b-bones, but this is for export to the game engine, so it is not possible to use any blender-specific features such as b-bones, drivers and so on.
Below is my current result, but it bends rather strangely and is extremely inconvenient to deal with. In case of a hand or a leg IK is rather obvious, but here is a cycle of four (on the gif there are even more, a separate IK on each bone except side ones and non-deforming bones to operate them).
And additional question: which bone and with which method I should connect to the global parent (not shown on images) to resize and rotate all the structure?