Tracking actors head and placing a little box above it.

[taraba]

Hi guys and girls.

First of all, I want to thank this community for loads of great tips and knowledge being shared here. Many times your posts helped me a lot.

The time has come to open my first thread and to ask my first question with a great hope someone will help me and point me in right direction.

We (my friends and I) plan to shot a few scenes with a guy walking in different environments. Our goal is to put a small box floating over that guy's head.

At first, I thought it will be relatively easy task: we take the footage, use Camera Tracker in Nuke or AE, solve the camera and a scene, use reconcile3d to convert desired points in 2D, import .obj file, attach the box on the right point and offset it in y-axis to the desired point above his head.

Of course, it's never easy as it looks.
Is our planned workflow right? Today, we made first tests and have a lot of doubts now.

What is the best way to track someone's head in a shot? It will rotate and move in X,Y,Z and we want that box to perfectly match the head's movement and to be above actors head. Maybe we should try to manually match the movement? At least to tray manually matching the x rotation? It would be a painful experience I know.

Which software is the best to track this kinds of shots? Maybe we should use markers?

Maybe I am just tired and don't see the obvious solution ?

Pls help me guys. Any kind of a advice is welcome.

Thank you in advance and wish you the best women, the best beer, a lot of great and interesting jobs, a lot of love and a lot of money...

[dcompz]

To track his head, you are going to want to look into object tracking. Most of the major matchmove software ( SynthEyes, PfTrack, Boujou, etc) will allow you to do this. It all depends on the footage though. If the camera does not move at all you can fake an object track out of Nuke but you will end up with a still object and a camera animated around it. A real object track will actually track a piece of geometry to follow the motion of an object in the plate.

If the camera is locked, you are better off just matchmoving by hand in a 3d app. Depending on the footage you may or may not need markers. Of course they will always be helpful but they will need to be painted out afterwards.

[scrimski]

Try tracking in Mocha, not just one feature of the head, but the whole head and adjust manually if needed.

[taraba]

thank you very much for your help guys... it was very very helpful...

we will test some solutions to see what we can do...