How do I set the internal and external parameters?

[yeluoo]

  # pyrender.Viewer(scene, use_raymond_lighting=True)
    
  renderer = pyrender.OffscreenRenderer(viewport_width=1024, viewport_height=1024)
  image, _ = renderer.render(scene)

  # 保存图片到文件
  filename = f'scene_{i:02}.png'
  import cv2
  cv2.imwrite(filename, image)
  print(f"Scene saved to {os.path.abspath(filename)}")

I want to render it into an image. How do I set the internal and external parameters? I set it to the unit matrix, and the rendering result is empty.
@TimoBolkart @soubhiksanyal @NeelayS