title: Vispy: How to draw only one quarter of a plane
body: <p>I want to show only 1 quarter of a plane, is there any method to do that? I've tried all options of <code>visuals.Plane()</code> but not successfully. I also tried to change value of <code>vertices['color']</code> and the result is same. Here is my code:</p>
  <pre><code>import vispy
  from vispy import geometry
  from vispy.scene import visuals, widgets
  from vispy.scene.cameras import TurntableCamera
  from vispy.scene import SceneCanvas
  
  class Vis():
      def __init__(self):  
          self.canvas = SceneCanvas(keys='interactive', title='vispy', show=True, size=(1280, 720))
          self.canvas.events.key_press.connect(self._key_press)
          self.grid = self.canvas.central_widget.add_grid()
          self.view = widgets.ViewBox(parent=self.canvas.scene,
                                  camera=TurntableCamera(distance=10.0))
          self.grid.add_widget(self.view)
          visuals.XYZAxis(parent=self.view.scene)
          vertices, faces, outline = geometry.create_plane(width=2,
                                                          height=2,
                                                          direction='+z', width_segments=1, height_segments=1)
          self.floor = visuals.Plane(width=2,
                                   height=2,
                                   width_segments=1, height_segments=1,
                                   vertex_colors=vertices['color'], edge_color='k', direction='+z',
                                   parent=self.view.scene)
  
      def run(self):
          self.canvas.app.run()
  
      def _key_press(self, event):
          if event.key == 'Q':
              self.destroy()
  
      def destroy(self):
          self.canvas.close()
          vispy.app.quit()
  
  if __name__ == &quot;__main__&quot;:
      vis = Vis()
      vis.run()
  </code></pre>