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Issue with a compositor. Matching fake 3D


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First i hope i didn't write in the wrong section.

Also i cannot post pics of the issue.


I have a compositor who asked me to match my 3D objects into his fake 2D with fake camera motions.

The shot is about someone falling in a pit, and i have to attach ribbons to her body.

The scene is a 3/4 view sideways, and he is faking the camera getting closer to her and rotating(very slightly) around her as she falls.


The shot is made like this:

-A fake background(the pit) with a rotating camera ( point A to point B with slight faked rotation around her)

-The singer( which was shot with a static camera 50 mm) simply up-scaled (fake camera zoom) and so slightly sqewed to match(kind of) the camera rotation applied on the background.


So what i did, is track his fake 2D/3D shot (mainly the singer), which is a fake camera zoom, and incorporated my ribbons.Which looks fine according to her perspective.

His problem is that it doesn't match with the rotation he is trying to fake(with the background) which is logic as the ribbons are attached to her (again she was filmed with a static camera).

He asked me to rotate my cam slightly, which i got from tracking the singer, to fake/match with the motion he apply on the background.


I just doesn't work,as she is static and the background rotates slightly.it is either one or the other.


I told him that i should match the camera to her, give him the elements and then he has to apply his fake cameras. Not the other way around


Did anyone of you worked that way before. Because as far as i know that is not how it should be done and it can't simply work.

Also he is insisting that it is 2016 and it can be done. Basically he is trying to make me look like i am the one not knowing what i am doing.

I probably lac some skills/knowledge, but i have never seen anyone track 2.5D and then apply real 3D on a shot that already has 2 different camera motions.





I would like your take on this issue.


Thank you




Edited by FR3D
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Thank you ChristianW.


That pretty much confirm what i thought and what i did.

The thing is that the guy is said to have experience in the compositing field (over 10 years), which let me confused about his requests.

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You might be able to do a camera track for the BG, and, an object track for the FG. Just ran a test in Syntheyes and it seems to work, though, not sure of your situation.



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Thanks marty,


You are right, but it wouldn't work in that shot because the ribbon are attach to her torso(which is an up-scaled static shot) so a rotation would make the attach point slide on her body.

I forgot to mention that i did a cloth simulation.


It is just not right to fake a camera rotation on objects attach to a body which itself doesn't have a camera rotation .


We went back to what i told them to do(the same as suggested by Christian) which was the only solution, to make the shot usable.


I think that guy pulled this stupid thing on me because he didn't want to redo a proper background animation.

He wanted me to adapt to his fallacious shot instead.



Thanks a lot for your support and help guys.

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