Align normal of plane to camera
I use a perspective projection camera and need to align a 3D plane so that it is facing the camera. I believe it has something to do with aligning the normal to the ray projected from the camera to the plane, but I'm not sure. I'm not too good at 3D maths so I don't really know how to go about doing this. Any help would be appreciated.
Homography is another way to do it (also existent in OpenCV)
Here is another link which you can use, if you know a little OpenCV