         }
     }
     
-    public var controlMethod: CTPanoramaControlMethod! {
+    public var controlMethod: CTPanoramaControlMethod = .touch {
         didSet {
-            switchControlMethod(to: controlMethod!)
+            switchControlMethod(to: controlMethod)
             resetCameraAngles()
         }
     }

        sceneView.scene = scene
        sceneView.backgroundColor = UIColor.black
        
        if controlMethod == nil {
            controlMethod = .touch
        }
     }
    
    // MARK: Configuration helper methods

                guard panoramaView.controlMethod == .motion else {return}
                
                guard let motionData = motionData else {
                    print("\(String(describing: error?.localizedDescription))")
                    panoramaView.motionManager.stopDeviceMotionUpdates()
                    return
                }
