The idea is to do exactly what CG Matter did here but instead keep the empty fixed in the global system, and have the camera move.

The camera is basically panning over a surface.

It seems as if the motion tracking preset "reconstruction tab" has only one of the possibilities covered, the camera being stationary, but what if you're trying to reconstruct the camera movement, which is simply an inverse situation.

  • $\begingroup$ Could you provide a brief description (1-2 sentences) of the videos content. Otherwise, once your reference goes down, this question won't be understandable. $\endgroup$ – Leander Sep 5 '19 at 22:35
  • $\begingroup$ Well the video is simply a camera panning over a surface. Linking empties to tracks is easily doable from the "reconstruction" tab, but applying the track to the camera so that it is moving instead of the empty, appears not to be as straight forward. $\endgroup$ – t8ja Sep 5 '19 at 22:52

What happens, when you press the Link Empty to Track buttons is, that an empty gets added with a Follow Track constraint. We can just add this constraint manually to another camera.

  1. Move the active camera to the position of your object.
  2. Duplicate the camera and rename it to Moving Camera.
  3. RMB RMB select the Moving Camera and ⇧ ShiftRMB RMB select the original Camera and direct parent the Moving Camera to the Camera by pressing ⎈ Ctrl⇧ ShiftP > Make Parent without Inverse. The G grab the Moving Camera and move it to the approximate where the object would be in the original Cameras view.
  4. Add the Follow Track constraint to the Moving Camera and set the Camera as the Object and Camera of the constraint. Choose the correct movieclip and track as well.
    constraint setup
  5. Then press Constraint To Fcurve on the constraint. This will bake the constraints movement to fcurves, which we can examine in the graph editor.
  6. In the graph editor flip the keys vertically by pressing ⇧ ShiftM > By Values over Value=0. values over value
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  • $\begingroup$ I already tried something similar. I did the "constraint to F curve" for the Empty and then copied the keys to the camera, but the camera ended up being placed in the same location as the Empty. The thing is, I want the relationship between the Empty and the camera to stay the same, but inverted movement wise. Which I guess would entail reversing the parenting like you did here. $\endgroup$ – t8ja Sep 6 '19 at 12:15
  • $\begingroup$ But I guess since the camera is just a special kind of empty it doesn't really matter. I'll mark your answer if I manage to to what I want. $\endgroup$ – t8ja Sep 6 '19 at 13:13
  • $\begingroup$ Your method works just as well. Just add the last step (6) to inverse the keyframes. $\endgroup$ – Leander Sep 6 '19 at 13:59

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