def gluLookAt(eyex, eyey, eyez, centerx, centery, centerz, upx, upy, upz):
    """Define a viewing transformation. 

    :param eyez: Specifies the position of the eye point. 
    :param centerz: Specifies the position of the reference point. 
    :param upz: Specifies the direction of the up vector. 
    """
    pass
