title: How to correctly use cv::triangulatePoints()
body: <p>I am trying to triangulate some points with OpenCV and I found this <code>cv::triangulatePoints()</code> function. The problem is that there is almost no documentation or examples of it.</p>
  
  <p>I have some doubts about it. </p>
  
  <ol>
  <li><p><strong>What method does it use?</strong>
  I've making a small research about triangulations and there are several methods (Linear, Linear LS, eigen, iterative LS, iterative eigen,...) but I can't find which one is it using in OpenCV. </p></li>
  <li><p><strong>How should I use it?</strong> It seems that as an input it needs a projection matrix and <strong>3xN</strong> homogeneous <strong>2D</strong> points. I have them defined as <code>std::vector&lt;cv::Point3d&gt; pnts</code>, but as an output it needs <strong>4xN</strong> arrays and obviously I can't create a <code>std::vector&lt;cv::Point4d&gt;</code> because it doesn't exist, so how should I define the output vector?</p></li>
  </ol>
  
  <p>For the second question I tried: <code>cv::Mat pnts3D(4,N,CV_64F);</code> and <code>cv::Mat pnts3d;</code>, neither seems to work (it throws an exception).</p>