@Override
    public void write(JmeExporter ex) throws IOException {
        super.write(ex);
        OutputCapsule oc = ex.getCapsule(this);
        oc.write(controlDir, CONTROL_DIR_NAME, ControlDirection.SpatialToCamera);
        oc.write(camera, CAMERA_NAME, null);
    }
@param camera The Camera to be synced.
@param controlDir SpatialToCamera or CameraToSpatial
jme3-core/src/main/java/com/jme3/scene/control/CameraControl.java