class GameViewController: UIViewController
{
    let controller = DaydreamController()
    var ship: SCNNode!
    var orientation0 = GLKQuaternionIdentity
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        controller.delegate = self
        controller.connect()
            
        ....

        // retrieve the ship node
        ship = scene.rootNode.childNode(withName: "ship", recursively: true)!

        // animate the 3d object
        // ship.runAction(SCNAction.repeatForever(SCNAction.rotateBy(x: 0, y: 2, z: 0, duration: 1)))

        ....
    }
}

extension GameViewController: DaydreamControllerDelegate
{
    func daydreamControllerDidConnect(_ controller: DaydreamController) {
        print("Press the home button to recenter the controller's orientation")
    }

    func daydreamControllerDidUpdate(_ controller: DaydreamController, batteryLevel: UInt8) {
        print("battery level \(batteryLevel)%")
    }

    func daydreamControllerDidUpdate(_ controller: DaydreamController, state: DaydreamController.State) {
        if state.homeButtonDown {
            orientation0 = GLKQuaternionInvert(state.orientation)
        }
        
        let q = GLKQuaternionMultiply(orientation0, state.orientation)
        ship.orientation = SCNQuaternion(q.x, q.y, q.z, q.w)
    }
}