Tracking objects that move off screen in Mocha

[Erik Waluska]

The link you tried to post didn’t seem to work but I just googled the title of your post and there’s quite a bit of info and tutorials out there about this. Here are a couple that may help:

How to track an object that goes off screen

https://vfxhaiku.com/2011/12/how-to-track-an-object-that-goes-off-screen-with-adobe-after-effects/

https://www.cgmotionbox.com/2012/01/tracking-an-object-that-goes-off-screen-in-after-effects/

https://forums.creativecow.net/readpost/2/1017437

Erik Waluska
EAWmedia

[Martin Brennand]

The youtube clip does not seem to appear, but you can track like this in mocha by simply adding a new spline to the layer, so before the object you are tracking goes off screen, you can stop the track and draw another shape around another area on the same plane and then continue.

Alternatively if you have a long track where the plane is fairly consistent, you can actually unlink the shape entirely from the track:
1. Draw your shape
2. On the left-hand panel click the drop down that says “Link to Track”
3. Choose “None”
4. Turn on the surface (The blue square icon) or turn on the grid
5. Begin tracking

What you will see is the shape will not move, but the surface/grid will start moving along. This is because the shape is no longer linked to the track and information is passing under the shape, providing the tracker with new information every frame.

This doesn’t always work, as you need to keep an eye on obstructions, but you can also stop the track and move the shape around then keep tracking. The shape does not control the track, so moving it will not move the tracking, it just gives it the search area to look for information.

Martin Brennand | Product Manager | mocha – Imagineer Systems

[Jimmy Walter]

I am tracking crows feet on a face. The face turns so the crows feet on one side are no longer visible and the tracking stops. The crows face come back into and leave the shot several times. How do I handle this?