@Override
    public void setGravity(Vector3f gravity) {
        super.setGravity(gravity);

        if (getSpatial() != null) { // TODO make sure it's in ragdoll mode
            PhysicsRigidBody[] bodies = listRigidBodies();
            for (PhysicsRigidBody rigidBody : bodies) {
                rigidBody.setGravity(gravity);
            }
        }
    }
Alter this control's gravitational acceleration for Ragdoll mode.

@param gravity the desired acceleration vector (in physics-space
coordinates, not null, unaffected, default=0,-9.8,0)
jme3-jbullet/src/main/java/com/jme3/bullet/animation/DacLinks.java