to start with what I like to accomplish (just a bit better) is :
That's the well-known 'Talking Tomatoe/-Orange'-effect, or what Conan O'Brian did for a while, talking portraits.
What you see in myYT-video is done in Motion WITH Motion's own tracker ...
The tracking points were the nostrils <eeks> of the guy, who, in real life, never laughs, Mr 110% in-control ... as you notice, 2-3x times the tracker lost track, could be fixed manually.
The insert group is a recording of an actor, a glued mustache and music from a very old pop-song, concerning Greece .... I masked the mouth and the mustache, soft border, some color correction - for a test that was a hit!
.......... since the NAB-discount offer from coremelt, I'm proud owner of TrackX and SliceX.
Since then I'm wrestling with in understanding what to do when. And why:
The Motion Tracker is just a tiny point; the Manual recommends high contrasts = nostrills.
Now, in TrackX-layer I'm asked to 'paint' a whole area for tracking - hm? He has deep wrinkles - should I draw my tracker-mask ON that wrinkle? Or aside? Should the tracking area been bigger than the later applied clip? Or smaller? Or same size? Could/Should I track the whole head?
#1 was my hand-drawn tracking area.
When you do step#2/Surface, that test-chart appears - much bigger than the tracker from!
Now, I should drop my replacement into the well:
The whole frame appears! That's wrong! pic #3
but the scale X and scale Y from coremelt, offer only 200% max - which is, in my case, not enough. (no, pushing the numbers with the mouse has no effect, it ramps a 200%).
So, I made my an interim blow-up, which fills the tracked area; this interim version is not 16:9, but fills the TrackX screen nicely.
For unknown reasons, the tracked area 'tilts', which leads to funny faces, #4
And finally; masking in TrackX is a bit tricky... 'the blur mask' does blur all content, not just the outside...
just to summarize, correct me when I'm wrong:
No need to track the final area; you can track bigger(?) or smaller. The tracking mask does NOT mask the content.... (correct up to now?)
What is a good tracking point/area for TrackX? Any reason to be precise?
Finally: the insert - 16:9? Than the zoom-factor has to be bigger than just 2x times.
Or a 'done', pre-produced 'stamp', with nice soft borders, and with the same form factor as the tracking-area?? (Lucky me, we recording 4k - allows a monster-zoom in post! LOL
The many examples of coremelt - my testing rebuilts worked with my material superb! - are based upon rectangles - what if I don't have rectangles?
... or, probably, I just have missed the tut which explains it all ...