At work we're using Unity game engine and I haven't done a lot of tests yet.
I assume you can use a stretchy spine feature, but would a broken joint hierarchy work?
I'm looking for a way to rig a spine, but I assume a broken joint hierarchy is not an option?
On all the ik spline spines I've seen they make it stretchy and use a broken hierarhchy structure.
When not using the stretchy feature and you'd constrain the arm directly to the spine_end_jnt you will get wobbles as it's conforming to a curve. To get rid of this you constrain the arms and head to the upperbody_ctrl and make the spine stretchy so when the upperbody_ctrl moves the spine stretch to reach, otherwise it will just look broken if you move the upperbody_ctrl. So now you obviously need to constantly check the scale of the spine and offset it if it's getting to short or long. This is the way I'm used to and will give you very good control over the spine.
But, would this work aswell when exporting to a game engine or should I abandon the IKspline an use FK explicitly?