APPLE MOTION: Motion Forum Motion Tutorials FCP Legacy FCP Tutorials

Tracking a group rather than source footage

COW Forums : Apple Motion

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
John McMullinTracking a group rather than source footage
by on Apr 2, 2013 at 3:59:43 pm


I'm trying to track a sign onto a background shot that has a flop on it. If I use match motion to track the un-flopped shot, then the movement goes the opposite way to what I want. To get around this, it seemed natural to me to nest the flopped background into a group and use that group as the source for the match motion effect.

Trouble is, when I drag the group into the source box for the match move effect, I seem to lose the controls to reposition the tracker points.

I got around this by rendering out the flopped background as a separate clip and reimporting it as the source. But I was wondering if there is a way to avoid having to do that in Motion. I often seem to have problems with grouping. It doesn't seem to be a straight equivalent to After Effects nesting.

Many thanks for you help,


Return to posts index

Simon UbsdellRe: Tracking a group rather than source footage
by on Apr 2, 2013 at 7:02:38 pm

Here's something that I tried that seemed to work and might be useful to you (or not!).

I grouped the action that I wanted to track and the object wanted to follow it (before doing any flopping) and then applied to Match Move behavior to the shape I wanted to move to follow the action and tracked away.

I then flopped the entire group - and both motions were flopped together as I imagine you want them. My action was originally moving right to left and with the flop it moves left to right, and my shape also moves left to right to keep up with it.

If the orientation of the shape is now wrong all you need to do is flop it the other way again - inside the group.

EDIT: What I meant to say was that to reorientate the shape to its original position you could add it to a new group inside the main one and apply the Match Move to that new group and then flop the shape layer inside the new group - if that makes any sense at all ;-)

I think that works - but it might not be what you're looking for.

Simon Ubsdell

Return to posts index

John McMullinRe: Tracking a group rather than source footage
by on Apr 3, 2013 at 7:50:36 pm

Thanks Simon.

I'm sure that would have worked for me. Means doing a double flop but that's no hardship.

I'm still a bit confused though by the nesting principle in Motion. Sometimes seems hard to treat groups as a flattened file.

Thanks again, John

Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 All Rights Reserved