I just learnt motion tracking in Adobe After Effects and I find it great. I need to track the (X,Y) location of the object that I am tracking. For Example, lets say there's a video of a black dot moving from the top left corner of a screen to the bottom right on a white board. I would like to know it's new location every time it moves. Like a list of (0,100) (1,99) (2,98)..... One Idea is taking a screenshot of the video every second, locating the dot and getting it's location from there. I'm sure that this is tracked in the background of motion tracking. Is anything like this possible?
1 Answer
This is definitely possible! Because you say you're new I'll write this out in detail, you might know some of this already but here goes:
Make a new composition with just your footage, and add a new Null Object (Layer>New>Null Object). Make sure this is just above your footage in the layer stack. It doesn't actually have to be, but if it is then it will simplify a few things.
Motion track your footage and in the motion tracking panel click "Apply" and then just hit "OK" on the dialog that opens up.
Now what happens is your tracking data gets applied to the Null Object (it automatically takes the layer above the footage layer - you can change this of course but no need to in this example).
Select your null object and hit "u" which is the shortcut to show all keyframes. You'll see that there are now position keys on the null object, and those are the coordinates you want already given in X and Y, with the top right corner of the screen at (0,0).
What do you want to do with them from there?
EDIT: Just realized an even simpler method... just motion track your dot, select your footage layer and hit "u". Now you will see a keyframed property called "Feature Center" and this is what you want. Everything in AE has (0,0) in the top left corner.
