Trouble applying TRACKING data from MOCHA to NULL or ...

[SandroTrunz]

Hi, dear community,

I'm trying to apply a 4-point motion tracker in Mocha to a "Graffiti" I drew myself in AE.

The 4-point tracker looks fine, ... and DISAPPEARS after FRAME 185! (out of frame)

When I apply it to a Null, which I then use to be parented to the 'Graffiti' ... it gets all funky.

I'm losing my marbles over this ...

Ths heaps in advance,
Sandro

[Rick Gerard · Accepted solution]

If you have not scaled or repositioned the layer that you tracked in Mocha AE the null should attach to the center of the surface you created in Mocha. I'm not sure where your workflow went wrong. To make sure that the latest release of AE doesn't have a bug I did a quick test. Here's a speeded-up over the shoulder. I always turn off the spline visibility, add a surface, and usually one of the grids when I'm tracking in Mocha so I can have a really good look at the track. Maybe this video will give you a hint. I tried to include everything I did.

[SandroTrunz]

Dear Rick_Gerard,

You are and absolute AE-whizz-genius.

This is wayYy more than I bargained for: Thanks so much for both the actual solution to my problem-ôh
   ----> SCALE 50% <----- 

SCALE was the VILLAIN

and your entire workflow. Learnt some extra tweaks and ideas therein too.

HOW can I SCALE a CLIP, TRACE it & create a NULL for it WITHOUT RUNNING INTO THIS IMPASSE?

Greetings from Switzerland,
Sandro 

[Rick Gerard]

Pre-compose the layer before you run the tracker in Mocha or Do everything in a larger comp and scale it down later.

I always try and work at the native resolution of the project. Just finished a compositing job where the camera original was Log 6K sent to me as an EXR sequence. My comps were created from the EXR sequence so everything matched. I put an adjustment layer as a guide layer with the basic LUT for the movie on the top layer so I could tell what the composite would look like because it's impossible for me to accurately judge anything if I'm looking at log footage, did all my compositing work, rendered the comp to the client's Open EXR sequence specifications. When rendering the Guide adjustment layer with the color correction applied was ignored and the client ended up with a VFX shot that exactly matched the camera original so no monkeying around with my 126 frames was required to make the FX match the rest of the footage in the scene. The final delivery was 4K so the Production Master and all of the tests for the client were delivered in 4K.

[SandroTrunz]

Phew! THAT is exhaustive (not 'exhausting', mind you)! 
I'll definitely copy-paste this workflow for future reference.
I bow my head in humble reverence - this all shows me that I'm naught but a mere 'basic' user.