Sets the current transform of this node to be the 'initial state' ie that position / orientation / scale to be used as a basis for delta values used in keyframe animation.
You never need to call this method unless you plan to animate this node. If you do plan to animate it, call this method once you've loaded the node with its base state, ie the state on which all keyframes are based. If you never call this method, the initial state is the identity transform (do nothing) and a position of zero
