SpriteKit Accelerometer issues

Question

I am making a game using sprite-kit. In my game I am using the accelerometer to move the node side to side by tilting the device. The following code works smoothly but after 8-10 game restarts, it kind of lags a bit to respond to the tilt. I then close the application and the problem repeats it self.

I have motionManger.startAccelerometerUpdates() in didMove(to view: SKView) and have a function that looks like so

    func processUserMotion(forUpdate currentTime: CFTimeInterval) {



    Ball.position.x += xAcceleration * 50 // xAcceleration is a variable that is a CGFloat = 0

    motionManger.accelerometerUpdateInterval = 0.1
    motionManger.startAccelerometerUpdates(to: OperationQueue.current!) { (data:CMAccelerometerData?, error:Error?) in
        if let accelerometerData = data {
            let acceleration = accelerometerData.acceleration
            self.xAcceleration = CGFloat(acceleration.x) * 0.75 + self.xAcceleration * 0.25
        }
    }


}

 override func update(_ currentTime: TimeInterval) {

     processUserMotion(forUpdate: currentTime)
 }

Any idea why this is happening or a better way to make the node respond well when the device is being tilted to left and right? Thanks!

UPDATE:

I finally figured out why the accelorometer was lagging. All I had to do was add motionManger.stopAccelerometerUpdates() to my GameOver scene. After doing so, I would transition back to GameScene 30 plus times and it responds well! Hope this little error helps someone in the future!

Did you check if the scene is being deallocated? If not, add deinit{print"deinit"} to your scene class and transition to a new scene. — 0x141E
Yes I did check and it is being deallocated. I found my solution. Rookie mistake! In my gameover function, I forgot to add motionManger.stopAccelerometerUpdates(). — sicvayne

Maetschl Maetschl · Accepted Answer · 2017-04-22T00:39:54

CMMotionManager.startAccelerometerUpdates must be used as a reference to one of your variables, it is not necessary to run it every time you generate a movement.

For example in Swift 3

class GameScene: SKScene {

    private var ballNode : SKSpriteNode?
    private let manager = CMMotionManager()

    override func didMove(to view: SKView) {

        self.ballNode = self.childNode(withName: "ball") as? SKSpriteNode

        manager.startAccelerometerUpdates()
        manager.accelerometerUpdateInterval = 0.01
        manager.startAccelerometerUpdates(to: OperationQueue.current!){ (data:CMAccelerometerData?, error:Error?) in
            if let accelerometerData = data {
                let acceleration = accelerometerData.acceleration
                self.ballNode?.physicsBody?.velocity.dx += 10*CGFloat(acceleration.x)
            }
        }


    }
    override func update(_ currentTime: TimeInterval) {
        //nothing here
    }
}

Source code: https://github.com/Maetschl/SpriteKitExamples/tree/master/CoreMotionTest

SpriteKit Accelerometer issues

1 Answers