Mocha Pro 2021 refuses to track when using copied layer

using Mocha standalone:
when i try to track a copy of a layer (before it has been tracked) i immediately get two error boxes (see attached image):
Tracking layer “[layer name]” terminated prematurely
One or more layers were not tracked properly. Try increasing the minimum percentage of pixels used.
i have not tried increasing the pixel percental (i am using the Essentials workspace), but if i create a new layer by redrawing a new bounding box then tracking will work properly.

has someone else seen this error? am i doing something wrong? is there a problem with copying layers?

thx, julian
my system is windows 10, GTX 1080, 64GB RAM

Hi Julian,

I would recommend you change into classic workspace and increase the pixels, i’d check the translate, scale, rotation, skew, and prespective boxes to track you object.

Hope it helps!


I am pretty sure the layer you have above this layer is occluding the layer (Mocha treats everything in the top of the layer pile as closest to the camera, so you can create holdout mattes). I think you have accidentally laid out your layer pile into a holdout matte. I can’t see for sure because it is turned off, but that’s what I think is going on.

thanks, mary. i will look into holdout mattes in Mocha. i know what they are in compositing software (eg Fusion), but i have never knowingly used them in Mocha. can i give you some more information so that you can determine whether i have laid out my layer pile into a holdout matte?

addendum: in the light of your comments and those of marc, i tried copying an existing layer and putting it at the top. same error. however, as mentioned to marc, if i drag the layer to the bottom, then re-run it, it tracks with ease. is this an illustration of the holdout matter? more strangely, when i drag this same newly copied layer back to the top - it now works! could this be a bug?

hi marc, i am deliberately working in Essentials to follow Ben Brownlee’s intro course, but of course i can investigate the Classic workspace and look up how to increase the pixels because i know this can be useful.

using a copied layer, placed at the top of the stack and checking all five boxes didn’t make any difference - i get the same error. BUT! if i drag the layer to the bottom, then re-run it, it tracks with ease. i thought that this might have been an illustration of what mary mentioned, however, when i drag this same copied layer back to the top - it now works! i cannot feeling that this is a bug. if not, it is somewhat inscrutable behaviour.

Let me see all your shapes on in Mocha?

yes, though, sorry to be dense, i am not quite sure what you mean. something like this?

No, in general, I need the whole screen to asses shapes. Turn they eye on all of them in the layer pile and capture the whole screen. Bonus if your turn mattes on and color code them (make the matte colors for shapes red, green, blue, etc.) I need to see what is going on and why you’d be getting that error.

is this better?

Yes. So just to make sure we are covering the bases here. Yes, your issue was layer order.

All your shapes are roughly the same size. All tracking layers are tracking when the gear is on, regardless of whether or not the eye icon is on for visibility.

So I stick to my original diagnosis, make sure the gears below each layer aren’t on or you’ll get that error.