title: pointcloud2 stream visualization in open3d or other possibility to visualize pointcloud2 in python
body: <p>I'm trying to visualize a pointcloud2 stream from a rostopic via open3d in python.</p>
  
  <p>This ist my code:</p>
  
  <pre><code>import sensor_msgs.point_cloud2 as pc2
  import open3d
  ...
  
  
  def callback(self, points):
          #self.pc = pcl.VoxelGridFilter(self.pc)
  
          self.pc = self.convertCloudFromRosToOpen3d(points)
  
          if self.first:
              self.first = False
              self.vis.create_window()
              rospy.loginfo('plot')
              self.vis.add_geometry(self.pc)
              self.vis.update_geometry()
              self.vis.poll_events()
              self.vis.update_renderer()
              self.vis.run()
          else:
              rospy.loginfo('update')
              self.vis.update_geometry()
              self.vis.poll_events()
              self.vis.update_renderer()
              self.vis.run()
  
      def listener(self):
          rospy.init_node('ui_config_node', anonymous=True)
          rospy.Subscriber('/kinect2/sd/points', PointCloud2, self.callback)
          rospy.spin() 
  
  </code></pre>
  
  <p>If I start this code I only get a frozen picture. </p>
  
  <p>I use <a href="https://github.com/felixchenfy/open3d_ros_pointcloud_conversion/blob/master/lib_cloud_conversion_between_Open3D_and_ROS.py" rel="nofollow noreferrer">this</a> script to convert the pointCloud2 to an open3d format.</p>
  
  <p><strong>If someone has another idea to visualize a pointcloud2 in rospy, I would be happy to hear it.</strong> </p>
  
  <p>Thanks for help and suggestions!</p>