Adobe After Effects Forum
Tracking tips on MOCHA
Tracking tips on MOCHA
by Rafael Braz on Jun 16, 2019 at 7:46:41 pm


I don't really use mocha in my usual workflow, thus I'm not really familiar with its functionalities, which are many. Not to mention the interface changes.

Even so I'm able to solve the problems I'm assigned to, along with eventual headaches lol.

Anyway, for personal use, I'm trying to track this video but facing some problems.
Without much trouble I was able to track his hand movements and the trombone.

But... as his body bounces and swings, the tracking can't follow it properly as the anchor point of this rotation movement is his head and I don't know how to or even if it's possible to set it up.

I'm not sure if I was clear with my words but the images will help out.
The "ruler" follows the instrument but not its rotation.
I tried to apply the null's rotation but it doesn't work all the way.

Any hints?

Thanks in advance.

Re: Tracking tips on MOCHA
by Martin Brennand on Jun 17, 2019 at 12:04:11 am

If you need the rotation on the head as opposed to the hand, one method you could try is:
1. Track the head AND hand
2. Export the tracking data from the hand track to the null
3. Delete the rotation data
4. Export the head tracking data and apply it to another null
5. Copy the rotation keyframes from the head null to the hand null.

I have no idea if this will actually work, as i'm only theorising here. ;)

Martin Brennand | Product Manager | Mocha - Boris FX (Imagineer Systems)

Re: Tracking tips on MOCHA
by Rafael Braz on Jun 17, 2019 at 8:53:04 pm

Oddly the closest result was using the corner pin.
But I couldn't make it "2D" nor un-distort it.

I will try your idea and post the results.

But there's gotta be an easy way... it's not that complicated...

Re: Tracking tips on MOCHA
by Richard Garabedain on Jun 17, 2019 at 3:05:59 pm

IN mocha, if the tracking is not working right than your pieces are too big. do the arm, hand and torso all separately.

Re: Tracking tips on MOCHA
by Blaise Douros on Jun 18, 2019 at 7:53:58 pm

In my opinion, there's absolutely no need to use Mocha for this. All you need to use is the After Effects point tracking system.

Pick two nice consistently-visible points--maybe the mouthpiece and the upper point of the bell--and track them for Position and Rotation with the two points that appear. Set the Attach Points a little above the hands, up on the trombone slide, and apply the Position and Rotation data to the graphic you're trying to attach. Adjust the Scale, Anchor Point, and Rotation properties of your graphic to align them, and you'll be done.

Re: Tracking tips on MOCHA
by Rafael Braz on Jun 18, 2019 at 9:04:51 pm

Thanks. You were absolutely right.

Re: Tracking tips on MOCHA
by Blaise Douros on Jun 18, 2019 at 9:28:48 pm

I was working on a comp today with this exact workflow, so the timing was good ☺