Thanks Jean!
But...is not a helpme much.
How can traslate this code in playmaker?
//Move each wall to its edge location:
topWall.size = new Vector2(mainCam.ScreenToWorldPoint(new Vector3(Screen.width * 2f, 0f, 0f)).x, 1f);
topWall.center = new Vector2(0f, mainCam.ScreenToWorldPoint(new Vector3(0f, Screen.height, 0f)).y + 0.5f);
leftWall.size = new Vector2(1f, mainCam.ScreenToWorldPoint(new Vector3(0f, Screen.height * 2f, 0f)).y); ;
leftWall.center = new Vector2(mainCam.ScreenToWorldPoint(new Vector3(0f, 0f, 0f)).x - 0.5f, 0f);
rightWall.size = new Vector2(1f, mainCam.ScreenToWorldPoint(new Vector3(0f, Screen.height * 2f, 0f)).y);
rightWall.center = new Vector2(mainCam.ScreenToWorldPoint(new Vector3(Screen.width, 0f, 0f)).x + 0.5f, 0f);