I am new to swift and making a game where the SKCamera is moving on the scene but I wanna keep the center of the scene updated when skcamera moves along. Just wondering what can I use.
What do you mean "keep the center of the scene updated when skcamera moves along" If you are using a camera, the camera is always the the center of the screen, and the entire scene is always updating. I am going to take a stab in the dark here and say you are not setting
scene.camera = SKCameraNode. Other than this, you will need to clarify what you are asking for.
Use this to set the camera to the ball after it passes a certain point:
camera.y = ball.position.y > scene.height/2 ? ball.position.y : scene.height / 2