title: transform 3d camera coordinates to 3d real world coordinates with opencv
body: <p>I'm working on a stereo vision system based on openCV which current return correct 3d coordinates, but in the wrong perspective.</p>
  
  <p>I have program a function which give me the camera-3d-coordinate and the expected real-world-coordinate from a cheesboard, but I didn't find out how to generate a transformation matrix from this data.</p>
  
  <p>All possible functions I found in OpenCV doesn't work because they work with 2d-coordinates on a image, and not with the calculated 3d coordinates.</p>