AE Tracker/Mocha Tracking Is Jittery When Applied To Elements

[Nickwhy90]

Hi guys,

I’m currently trying to motion track green screen markers on a shot I’m working on, then apply the tracking to a background clip along with a few other elements, so when I have only the keyed object from the green screen, the rest of the elements would move along with its camera motion. When I’m in Mocha the track looks normal, but back in AE, when I create a Null and export the tracking using the corner pin (support motion blur) or the transform options and then tie the other assets to the null, I see a lot of jitter and and everything shakes. it's the same thing when I try to motion track with AE's tracker.

After a while it dawned on me that the background clip I want to use is with a different frame rate (23.98) than the green screen shot I’m tracking (25), so I interpreted the green screen shot in AE to be 23.98 too, but that didn’t make a difference. I turned off the motion blur I had added earlier to see if it would turn out to be the issue, but with no difference. While the main comp’s size is 3840x2160, the background asset clip’s resolution is 4096x2160, but I’ve precomped it to have the standard 4k res and I’ve applied the Mocha track on the precomp, so it shouldn’t be problematic. I also created a precomp for the night city background shot where I prolonged it to reach the necessary length by creating copies and keyframing the opacity.  Here are screen recordings and images for reference:

Screen Rec Vid

Green screen shot:

I don’t know what other info could be important in this case. I’d be thankful for any suggestions.

Thank you.

[ToolfarmJP]

Would you use a trial version of mocha full version to compare it with the AE bundle version? The download link is as follows.

https://borisfx.com/downloads/?product=mocha&host=adobe&os=windows%2bmac

[takashi vfx]

you have frame blending on. not sure if that affect but try toggle on and off to see any change. also your footage looks bigger than your comp. do you have any scale or repo on the footage. make sure the footage is the same size as comp, or just to recomp to make it so.

hope that helps

t

[Roland Kahlenberg]

You're mixing up frame sizes and frame rates - either of these will cause issues when compositing the tracked data onto your backplate.