i start to learn ae , and i want to make track and blur 3 object in video
i learned 1 method .. mask and modify it , but i think if i can track it and then apply the effect it will be fast and easy
i try several time but fail , when i apply the track data from mocha to the first comb it change and get small , undo , dup , apply track , same , undo , add null , apply to it , add the effect , nothing
so how i can do it
I'm not quite following your workflow, but it sounds like this page would really help you: After Effects Help | Tracking and stabilizing motion
Depending on what you're trying to do, the rigid mask tracker might be ideal.
You could either use mocha or the mask tracker (which is only available in AE CC).
To get started with mocha, see
(at about 30:00 I show how to get a mask from mocha to AE)
For the mask tracker, my tool MaskTracker+ is also useful. See these one minute tutorials: