@Override
    public void update(float tpf) {
        verifyAddedToSpatial("update the control");
        if (!isEnabled()) {
            return;
        }

        if (torsoLink != null) {
            torsoLink.update(tpf);
        }
        for (BoneLink boneLink : boneLinkList) {
            boneLink.update(tpf);
        }
    }
Update this control. Invoked once per frame during the logical-state
update, provided the control is added to a scene. Do not invoke directly
from user code.

@param tpf the time interval between frames (in seconds, &ge;0)
jme3-jbullet/src/main/java/com/jme3/bullet/animation/DacLinks.java