Tracking 90 degree motion?

I’m trying to track a thick sign that is slowly rotating.

So, we have a very clearly defined plane, and it seems like a not-so-challenging track to do.


I start at the angle when the sign is facing the camera, so almost zero deg.

As the sign rotates close to being 90 degrees to the camera, with rather strong parallax, Mocha Pro loses track.

  1. Is there a way to improve how Mocha “grabs” the track on rotation? I realize it cannot track the plane when it becomes completely invisible at 90 deg, to the camera, but I feel Mocha just loses track too early…

  2. The sign happens to be a cube. So as one side goes out of view (90 deg, see above), another side goes fully into view, at exactly same rate of motion/rotation. I only need to track one side (replacing the text there). Is there a way to somehow track the 2nd side, which we know stays at constant angle to the one we want, and “project” its motion onto the last say 10 degrees of the “bad” side just as it starts to disappear from view and Mocha loses its track?

I’ve been trying for a couple days now, and can’t find the solution…

Help! - Thanks in advance!

Hi there,

I usually handle the last few frames before there’s no more information to track with manual tracks. Track until the data goes badly, and then switch to manual track, hand animate the last few frames using the surface tool and end the layer there by trimming the layer in the layer controls. We can’t track where there’s no more texture.

Please let me know if you have any questions and I will be happy to help you.

Thanks Mary, I’ll try this now. Never did Manual before.

Also… is it me, or switching to “use 100% of pixels” and Small Motion did help Mocha keep the handle on things (no pun intended) for longer? I think I won about 20 frames well-tracked with those settings!

Oh, and most importantly… is there any way to track something in a different plane to help this plane?

In the situations when relationship between the planes is known and constant (like sides in a spinning cube - we know they are at 90 degrees to each other all the time!), perhaps we could somehow tell Mocha: hey, track THAT plane, but apply it at 90 degree to THIS other plane! …possible???

It’s not just you, the percentage of pixels tracked is increasing that much more time mocha is spending to match that percentage of pixels. So instead of trying to match 20% and move on, it’s trying to match 100% before it looks for the next frame. It takes longer, but should be your first step when trying to get a better track.

You can’t track multiple planes and have it be the same data in mocha, it’s not a true 3D track. It’s a planar track. You can, however, use translation, scale, and rotation only to track similarly moving planes when you lose all data.

Got it on pixels %, many thanks again!

So I track plane #1 with all boxes checked, but a similarly moving plane #2 without checking perspective. Apologies if this is an elementary question, but then how do I apply plane #2’s track to the missing part of plane #1 track?

Yes, just move your shape to the next plane and turn shear and perspective off… but you wont get angle changes. That’s only useful for similarly moving objects when they go off screen. It might help your cube, but you’re almost certainly going to need to manual track some frames.