title: convert 3D plane to 2D
body: <p>I have a set of point cloud forming a plane in 3D, which I've obtained from RANSAC plane fitting. For some specific kind of analysis of the data I need to convert this to a 2D problem so that I can have all the z-values almost same. Suppose the equation of the plane is ax+by+cz+1=0. My question is that:</p>
  
  <ol>
  <li>How can I get the values of a,b,c from raw point cloud data? Will least square be the best approach or there is any way to obtain these values from RANSAC fitting?</li>
  <li>From some tutorials I got an idea about doing the following steps: translate to centre of mass, rotate about x-axis, rotate about y-axis, then un-translate again. Does it make sense? 3. How can I get the rotation angle in terms of a,b,c?</li>
  </ol>
  
  <p>I need some general idea of converting a 3D plane to 2D so that all the z-coordinate values are same.</p>