This question came from someone using BipedPlus. We are sharing it in case others are wondering the same thing.
For an in-place shot, Root(Ctrl_World) does not need to move. If a traveling shot is keyed on Bip001, moving Root(Ctrl_World) afterward throws the walk off. Moving only Root(Ctrl_World) leaves the foot IK on the ground, so the feet slide.
Previously, an export script parented the travel to Root, held Bip001, and kept only the height. How should this be done with BipedPlus?
This is usually called root motion. Where the horizontal travel sits, and where the height stays, differs from studio to studio.
BipedPlus gives you a finished rig hierarchy. Having Bip001 under Root(Ctrl_World) is a normal setup. While you animate, move Bip001 and leave Root(Ctrl_World) where it is. If both carry the travel, the walk doubles up. If only Root(Ctrl_World) moves, the feet slide.
One way to split it afterward: animate first, then store Bip001’s world position on each key. Put only X and Y, without height, on Root(Ctrl_World), and bake X, Y, and Z on Bip001. The difference between them is then only the height. Clearing the horizontal keys on Root(Ctrl_World) leaves an in-place shot.
Studios often keep this pre-export step as a button in their own tools. We have been waiting to add it to the Animation tab, because the demand is not clear yet. If you need it, if people around you need it, or if you have an example of the behavior you want, please tell us. It will help later development.
In short, if you restore the hierarchy to the state from before the script runs, you can write and run a root-motion script in the way that fits your work. When it finishes, please put the hierarchy back.