title: Get x,y,z cord from cv::Mat
body: <p>With reprojectImageTo3D(..) I get an Mat with 3D Points. Now I want to access the x,y,z values of these Points. But I don't know how I can do this?</p>
  
  <p>I tryed something like this: </p>
  
  <pre><code>(new3d.row(100).col(1)).x 
  </code></pre>
  
  <p>But it don't seems to work this way. </p>
  
  <p>I would be very thankful for any help here.</p>