I was doing a simple track and was having the same issues many other were having where the result in AE was getting pixelated and scaled in an odd way.
After doing some testing, I think I found out why and want to know if there is a solution in the Mocha interface, or a workaround, or if it is somthing that should be added to the mocha application.
Here is what I found out after some testing:
In summary, I found that the scaling would go ‘bad’ when you started the track midway in the footage, and then started tracking backward and the track got smaller as the footage went backwards. So in other words, tracking an object that started small and got larger in the footage, but you started the track when it was larger and had it track backwards to get the tracking data. What it looks like is mocha ends up taking the scale/pin data on the first frames to set the baseline for the insert clip, when ideally you want to be able to tell it a certain farme to use as ‘100%’ so that if it tracks backwards it scales down, rather than using the first frame as the baseline scale.
It is hard to articulate, but let me try to explain with some screen shots:
Here is an example of footage of a bus going by, and I want to track a window and insert some text on the window:
Here is the first frame:
Image: http://twinvision.com/images/forum-3.jpg
Here is a midpoint frame that I actually want to use to make the tracker (this is the important part of this!!!):
Image: http://twinvision.com/images/forum-2.jpg
Here is the last frame of the footage:
Image: http://twinvision.com/images/forum-3.jpg
As you can see, the first and last frames have a lot of motion blur and would be difficult to try to make a track on, so the idea is to make a track in the midpoint and then manually adjust the track for the start and finish, however this is what end up being the cause of the odd scaling pixilated results in AE.
So let me keep going here with the explaination and test results:
So here is a pic of the track I made at the midpoint frame and the insert clip overlayed and in place:
Image: http://twinvision.com/images/forum-4.jpg
I used that midpoint frame to actually create the insert clip in photoshop, so at that frame the insert clip very close to it’s actuall size.
Now here is where it gets interesting!!!
If I start the track, BUT ONLY TRACK FORWARD, and in this case the track gets smaller as the bus drives past, here is the mocha scale results for the midpoint frame:
Code:
Scale
Frame X percent Y percent Z percent
477 100 100 100
Now, if I import that into AE, the track works great and there is no pixelation or odd scaling, pics from AE:
Image: http://twinvision.com/images/forum-5.jpg
The problem here obviously is that it is only tracked from that point forward, so we have an incomplete track, I need it from that point going backward in the footage as well, so when I go back to mocha and track BACKWARD and the trackign object is getting smaller, here is the new mocha scale results for the midpoint frame:
Code:
Scale
Frame X percent Y percent Z percent
475 2031.82 2031.82 100
LOOK AT THOSE SCALES!!! So as you can see, with those scale levels, the translation to the insert clip between those and the pin data make the AE result pixelated:
Image: http://twinvision.com/images/forum-6.jpg
This is because in this case, as you track backwards, the track gets smaller and by the time we get to the first frame, the track is very small, yet moca sets its scale to 100%…when what we really want is to tell moca that 100% should be back at the midpoint frame and to scale using that as the baseline, so it would scale down as it move away.
Conclusion:
So I see a few options as a solution, some more as work-arounds and some more practical:
Possible ‘hack’ work around
I have not tried this yet, but maybe include a ‘junk’ frame as the first frame, and manually adjust the track to be 100% in size, so that it will always scale down or up from there?
Best solution
Maybe there is somthing like this already or a way to do the tracking/adjusting to solve this, but I would love to see an option in mocha where you can set the ‘scale base’ frame, such that it will use that frame as 100% and scale up or down from there when it goes backwards or forwards, and then make the proper scale/pin data relationship…this would solve any of the issue with the pixelation/scaling when importing the data to AE.
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