code: def test_plane_depth():
      with TestingCanvas(size=(80, 80)) as c:
          v = c.central_widget.add_view(border_width=0)
          v.camera = "arcball"
          v.camera.fov = 0
          v.camera.center = (40, 40, 40)
          v.camera.scale_factor = 80.0
  
          # two planes at 45 degrees relative to the camera. If depth is set correctly, we should see one half
          # of the screen red and the other half white
          scene.visuals.Volume(
              np.ones((80, 80, 80), dtype=np.uint8),
              interpolation="nearest",
              clim=(0, 1),
              cmap="grays",
              raycasting_mode="plane",
              plane_normal=(0, 1, 1),
              parent=v.scene,
          )
  
          scene.visuals.Volume(
              np.ones((80, 80, 80), dtype=np.uint8),
              interpolation="nearest",
              clim=(0, 1),
              cmap="reds",
              raycasting_mode="plane",
              plane_normal=(0, 1, -1),
              parent=v.scene,
          )
  
          # render with grays colormap
          rendered = c.render()
          left = rendered[40, 20]
          right = rendered[40, 60]
          assert np.array_equal(left, [255, 0, 0, 255])
          assert np.array_equal(right, [255, 255, 255, 255])
  
imports: import pytest
  import numpy
  from vispy import scene
  from vispy.testing import TestingCanvas, requires_application, run_tests_if_main, requires_pyopengl, raises
  from vispy.testing.image_tester import assert_image_approved, downsample
  from vispy.testing.rendered_array_tester import compare_render, max_for_dtype
label_desc: Use image node_id 11 for calling a global function with example usage: test_plane_depth() without return types