title: How to calculate the new camera position and rotation in a 3d space to get the exact same view of an 3d object after it is moved?
body: <p>I have a 3d object (Obj) and a camera (Cam) points to the object. The camera FOV, resolution, position and rotation are given along with the object's position and rotation.
  Then, we change Obj's position and rotation by some random numbers (known). What I need is to get the exact the same view of Obj as it is in its original position by only changing Cam's position and rotation.
  How to calculate the new camera's position and rotation?</p>