(self, parameter)
3D pan (only x,y).
3D pan (only x,y).
3D pan ( only x y ) .
def pan(self, parameter):
        """3D pan (only x,y)."""
        self.tx += parameter[0]
        self.ty += parameter[1]
def pan ( self , parameter ) : self . tx += parameter [ 0 ] self . ty += parameter [ 1 ]