After Effects Motion Tracking from outside of frame.

[Kevin Camp]

mocha is a tracker that can track a point if it leaves the frame, however, you will need to be tracking multiple points that form a plane for it to work. this tutorial shows how that works.
https://library.creativecow.net/articles/rabinowitz_aharon/Mocha_Tut_1.php

or you may be able to track a second point after the first leaves the frame, then combine those tracks. video copilot has several tutorials where andrew uses this technique… here’s one.
https://library.creativecow.net/articles/kramer_andrew/Set_Extensions.php

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Roland R. kahlenberg]

The proper term is Offset Tracking. And you don’t need seperate trackers. Perform a COW Search and there should be ample info for you in the AE forum as well as AE and Mocha tracking tutorials.

HTH
RoRK

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[Steve Dann]

Thank you guys, as long as the information is out there somewhere I’ll find it. Offset tracking sounds like a good idea. I can’t help thinking I saw a video tutorial a year ago that dealt with this but involved expressions.

[Steve Dann]

What I really meant to say was THANK YOU !!!!! I looked on Andrew Kramer’s site but didn’t know ‘set extension’ was what I needed to learn. That’s the BEST video tutorial for AE I’ve EVER seen. THANK YOU for pointing it out to me.

[Roland R. kahlenberg]

That’s Eran’s COW Tutorial. The expression Eran used involves the Continue method. It’s a good technique if there is no object within the shot for you to apply Offset Tracking.

Cheers
RoRK

Sell your AEPs with broadcastGEMs’ DVD series of templates. Click here for more

[Steve Dann]

I’ll look that up. Many thanks. What I’m trying to do is corner pin some thing (say an advertising hoarding) as it enters and leaves frame.