创建多个Kivy Canvas图像并导出为png:如何在管理kivy.clock的不可预测性的同时做到这一点？

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.graphics import Rectangle
from kivy.clock import Clock
from kivy.core.image import Image as CoreImage
import os

class MyWidget(Widget):
    def __init__(self, **kwargs):
        super(MyWidget, self).__init__(**kwargs)
        self.last_tick = 0
        self.frame_interval = 1 / 30  # 30 FPS
        Clock.schedule_interval(self.update, 1/60)

    def update(self, dt):
        current_time = Clock.get_time()
        if current_time - self.last_tick >= self.frame_interval:
            self.last_tick = current_time
            self.export_image()

    def export_image(self):
        with self.canvas:
            Rectangle(pos=self.pos, size=self.size)
        core_image = CoreImage(self)
        core_image.export_to_png('image_{}.png'.format(int(Clock.get_time())))

class MyApp(App):
    def build(self):
        return MyWidget()

if __name__ == '__main__':
    MyApp().run()

import threading
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.graphics import Rectangle
from kivy.core.image import Image as CoreImage

class MyWidget(Widget):
    def __init__(self, **kwargs):
        super(MyWidget, self).__init__(**kwargs)
        self.timer = threading.Timer(1.0 / 30, self.export_image)
        self.timer.start()

    def export_image(self):
        with self.canvas:
            Rectangle(pos=self.pos, size=self.size)
        core_image = CoreImage(self)
        core_image.export_to_png('image_{}.png'.format(int(threading.get_ident())))
        self.timer = threading.Timer(1.0 / 30, self.export_image)
        self.timer.start()

class MyApp(App):
    def build(self):
        return MyWidget()

if __name__ == '__main__':
    MyApp().run()