title: ( PCL createViewPort ): multiple poinclouds spin simultaneously in window
body: <p>I am going to create two viewport in order to visualize two independent point cloud.
  Here is a part of my code:</p>
  
  <pre><code>PORT1 = 0; PORT2=0;
  
  vis-&gt;createViewPort (0.5,0.0,1.0,1.0,PORT1);
  vis-&gt;setBackgroundColor(0,0,0,PORT1);
  vis-&gt;addPointCloud&lt;pcl::PointXYZ&gt;(*cloud1, "left cloud",PORT1);
  
  vis-&gt;createViewPort (0.0,0.0,0.5,1.0,PORT2);
  vis-&gt;setBackgroundColor(0.1,0.1,0.1,PORT2);
  vis-&gt;addPointCloud&lt;pcl::PointXYZ&gt;(*cloud2, "right cloud",PORT2);
  </code></pre>
  
  <p>the visualizer shows cloud1 and cloud2 in the same window. But when i want to change the view of one pointcloud (using mouse), the other spin simultaneously . Is there any way to make different pointclouds to view independant from each other? (I have created the visualizer in a thread and so I can not create two different visualizer)</p>
  
  <p>Thank you every body</p>