How to set camera tracking of an object in spritekite?

Question

iOS

Hello. I'm trying to set the camera to track an object, but the object moves up when loading.

class GameScene: SKScene, AnalogStickProtocol {
    
    var oval: SKSpriteNode?
    var World: SKNode!
    var Camera: SKNode!
    
    let moveAnalogStick: AnalogStick = AnalogStick()
    let rotateAnalogStick: AnalogStick = AnalogStick()
    override func didMoveToView(view: SKView) {
        //camera
        
        self.World = SKNode()
        self.World.name = "World"
        
        addChild(self.World)
        self.Camera = SKNode()
        self.Camera.name = "Camera"
        self.World.addChild(self.Camera)
        
        /* Setup your scene here */
        let bgDiametr: CGFloat = 120
        let thumbDiametr: CGFloat = 60
        let joysticksRadius = bgDiametr / 2
        self.backgroundColor = SKColor.yellowColor()
        moveAnalogStick.bgNodeDiametr = bgDiametr
        moveAnalogStick.thumbNodeDiametr = thumbDiametr
        moveAnalogStick.position = CGPointMake(joysticksRadius + 15, joysticksRadius + 15)
        moveAnalogStick.delegate = self
        self.addChild(moveAnalogStick)
        rotateAnalogStick.bgNodeDiametr = bgDiametr
        rotateAnalogStick.thumbNodeDiametr = thumbDiametr
        rotateAnalogStick.position = CGPointMake(CGRectGetMaxX(self.frame) - joysticksRadius - 15, joysticksRadius + 15)
        rotateAnalogStick.delegate = self
        self.addChild(rotateAnalogStick)
        //camera 
        
       
        
        
        oval = SKSpriteNode(imageNamed: "oval2")
        
        if let aN = oval {
            aN.physicsBody = SKPhysicsBody(texture: aN.texture, size: aN.size)
            
            aN.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame))
            aN.physicsBody?.affectedByGravity = false;
            
            //World.insertChild(aN, atIndex: 0)
            World.addChild(aN)
            
        }
        self.physicsBody = SKPhysicsBody(edgeLoopFromRect: self.frame)
        
   
       
        if let aN = oval {
            Camera.position = CGPoint(x: aN.position.x, y: aN.position.y)
            self.centerOnNode(Camera)
        }
        
        
    }
    
    
    
    override func didFinishUpdate() {
        
    }
    
    
    
    func centerOnNode(node: SKNode) {
        
        let cameraPositionInScene: CGPoint = node.scene!.convertPoint(node.position, fromNode: World)
        
        node.parent!.runAction(SKAction.moveTo(CGPoint(x:node.parent!.position.x + cameraPositionInScene.x, y:node.parent!.position.y + cameraPositionInScene.y), duration: 1))
        
    }
    
    // MARK: AnalogStickProtocol
    func moveAnalogStick(analogStick: AnalogStick, velocity: CGPoint, angularVelocity: Float) {
        if let aN = oval {
            if analogStick.isEqual(moveAnalogStick) {
                aN.position = CGPointMake(aN.position.x + (velocity.x * 0.12), aN.position.y + (velocity.y * 0.12))
            } else if analogStick.isEqual(rotateAnalogStick) {
                aN.zRotation = CGFloat(angularVelocity)
            }
        }
    }
}