'sets image for animation'

def animation(self):

    if ((self.current_time - self.animate_timer) > 30):
        if (self.frame_index < 3):
            self.frame_index += 1
        else:
            self.frame_index = 0
        self.animate_timer = self.current_time
        self.image = self.frames[self.frame_index]
