Stereo matte render broken in right view - please help

I’m in the middle of a big stereo roto job and just ran into a new render bug in 2019 v6.1.2 -

It appears that the bottom/right eye is being rendered with splines from the top/left eye.

My roto splines are fine in Mocha. Here’s the matte view of the left and right eyes-

Left eye:

Right eye:

Here’s the AE render with Apply Matte checked and all same splines visible:

Here’s a close up of the character. You can see the matte shifted right:

It looks to me like the plugin is rendering the bottom eye with the top matte.

Stereo rendering was working fine in earlier versions of Mocha. This seems like a new bug.

This is a difficult and time consuming roto job. I need to keep working and I need to be able to get a proper render when I’m finished. Please advise.

Thanks for your help!


Here’s another example.

Left/Top view:

Bottom/Right view:

In this example, it appears that only the left leg and left foot splines are affected.

This is a mess. Any help much appreciated.

Hi David,
Can you please share the Mocha project? If possible please share the first frame of the shot as well for reference.
Instead of Apply Matte, do you get the same result if you “convert splines to native AE masks”? Also curious if the same issue happens if you render and export your mattes externally out of Mocha? (Export rendered shapes).

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Hi Ross,

Thanks for the reply. I’ll run those tests and share my project with you and your team on DropBox later this morning. Stand by.

Hi Ross,

Here’s confirmation of the bug with Apply Matte. I converted the splines to AE masks in the plugin and they are correct in the right eye. Here’s a screen grab with the AE masks visible and the matte applied. The right eye matte is getting data from the left eye splines for the left leg and foot:

I can’t use AE masks as a workaround because I need Mocha feathering and motion blur for this project.

I’l send you a test project later today. Thanks.

Thanks for that confirmation. I would suspect that your best available workaround will be to render these out of Mocha as mattes. I will see if I can recreate on my end.

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I’ll give rending mattes out of Mocha a try.

I tried rolling back all the way to version 6.0.3 and still had the same problem. I’m wondering if it might be due to an AE update? I’m using AE version 16.1.2.

I know this has worked fine before so something’s changed somewhere.

Please keep me posted and let me know if you still want to see my project.


I just did a test with both Mocha Pro 6.1.1 and 6.1.2 inside Adobe AE 16.1.1 and could not reproduce the problem. I am updating AE now and will let you know.

Thanks, if I need to roll back AE I will.

I just did a test matte export and unfortunately, the problem is still there so this won’t work as a workaround:

Also note the odd ghosting at the bottom of each eye. This looks like a spline moving off screen but there’s nothing there in my project.

Please keep me posted. Thanks!

I’ve uploaded a short clip here:
Dropbox - - Simplify your life

The ghosting seems to be a bug with motion blur rendering. The matte on the right eye can be seen jumping to the wrong splines.

Hi Ross,

Ugh. Just did another test with the Mocha Pro standalone. Same problem.

If I’m seeing this in the standalone, does that mean my spline data is bad?

How can it be that my splines preview and animate fine in Mocha, and export fine as AE masks, but are completely messed up when rendered as mattes?

I have a lot of time already sunk into this project, am on deadline, and am running out of workarounds. I really hope there’s a way to make this work.

Thanks for your help!

Hi David, so if you turn motion blur OFF does the problem disappear?

Hi Martin,

Motion blur is keyframed on many of the splines. I’ll do a test on a small section and see if that helps with the motion blur artifacts. I’m not sure it will help with the stereo spline issue but maybe it will. Will test and let you know.

Hi David,

I’ve just done a base test and it’s definitely a problem with the motion blur settings in Mocha not working in stereo. Turning them on only renders the left matte as far as I can tell, while turning them off renders correctly. I’ll try to regress this if you think this was working correctly before.

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Hi Martin,

I just confirmed that yes, turning off motion blur fixes both the stereo spline issue and the artifacts. My mattes are now rendering properly with motion blur off.

I must not have been using motion blur on previous stereo roto sessions.

There’s a lot of motion blur in this project and it would be very useful to have it working for this job.

Is there any previous Mocha version where motion blur works properly in stereo?


Ok: The bad news is it doesn’t look like motion blur works in stereo even as far back as v5.6.0.
This means you’ll have to either:
a) Manually feather the blur with edge width
b) Use third-party motion blur in your comp.

We’ll investigate the problem, but unfortunately I don’t have a short-term solution for you at present :frowning:

Yikes, that goes quite a ways back. :open_mouth: Please put a fix on the request list.

In the interim, guess that means I’m deleting all the motion blur. Bummer. At least I can keep moving forward, so that’s good news.

If you or your team find any quick solutions, please let me know.

Thanks Martin!