Inconsistent scene display upon scrubbing vs. preview/render causes jerky animation

Report · Aug 24, 2023

Hi,
I have a 2D hand rig (parented PSD layers with some basic scripts for IK and pointing, DuIK and custom) which worked fine in 20018-2019 versions (older PC).
Now, in 2022 and 2023 same project (newer PC) throws curveballs at me - even I get smooth animation with scrubbing, the objects (rig controls, layers) start to jump and jerk around as soon as I try to preview them. Also, there I see some inconsistencies between rendered pixels and layers wireframes even after I do cache+mem purging.

Even changing some layer visibility impacts the inconsistencies, just at different frames, worst thing to nest 12.5fps animation com to 25fps main comp (or setting all to 25fps and adding PosterizeTime effect).

The worst part is, I have a copy of this very comp with expressions links to the rig controls, so its animation automatically updates in both comps. When I compose those two one over another, the output in both differs.
Disabled multi-frame rendering, latest Nvidia Studio drivers, disabled hardware acceleration, Final Quality previews - similar behavior in both latest AFX2022 and AFX2023.

Different scene with same rig, experiencing same issues. I could have blamed the rig, yet I can't spot any sudden property changes upon those jerks, and incorrect previews make me think it has something to do with AFX (or how it talks to GPU) itself.

Anyone, similar issues? What to knock?

Report · Aug 24, 2023

Hi @CucaramblaX,

Thank you for reporting this issue. Would you be able to share this project with us so that we can see the animation differences you are describing? Also, which version(s) of After Effects were working as expected with this project?

Thanks for reporting this issue and for any further information you can provide,

- John, After Effects Engineering Team

Report · Aug 24, 2023

Yes, very similar issues here. Rigged character with duik, and Joysticks & Sliders. It's unresponsive in more complex scenes, painfully slow in quite simple scenes. And yes it is not possible to scrub though on the timeline. I also have an issue where any change in any comp makes the whole thing have to RAM preview the whole master comp from scratch. It's really really annoying.

Report · Aug 25, 2023

Hey @JohnColombo,

Yesterday, I poked around the rig, and discovered the cause of aforementioned inconsistency - it was DuIK IK solver's Auto-Stretch feature - as soon I disabled it, the rendered pixels snapped to layer's wireframe position, which in turn ruined the animation itself, but was fixable.

The rig was made with DuIK v15; in later versions they introduced different rigging approach. The Stretch feature itself just automates the affected layer's Positions, yet it apparently somehow has an impact on how AFX renders data.

Today, (after PC reboot) opening the same scene, the main comp played back flawlesly, yet it lasted just until I started to dig into subcomps. So it has smth to do with software-hardware relationship.
The earlier version of AFX with working rig I just tested, was 15.1.2. It worked with earlier versions, although I also noticed that there I had same issue with actual vs. rendered version. Since there I got expected smooth result, I could not care less to dig under the hood.

Unfortunately, I cannot attach aep/zip/rar file as those are not supported. Here is a temporal storage link to https://failiem.lv/u/zrq7hurag (2 weeks from now). I cannot share it with artwork, however AEP should be enough to see the behavior.
The points of interest are comp("kidHand_R").layer("C_b3") and layer("b2"), the main comp("!E03_13-100").
My computer specs:

Dual monitor setup - Samsung U32J59x (4K) and LG IPS FullHD

Report · Aug 31, 2023

Hey @JohnColombo,
After doing more scripting, I realized that mismatch between layer's position and rendered pixels happens when there's cyclic dependency introduced. In my case, apparently, some rigging-parenting-scripting was the issue, but it could not be told until I loaded the project into newer AFX.
If this is really the case, then for the future releases, AFX could (at least) spit some kind of warning for that (like Maya does), so that user is prepared for potential issues.

Report · Aug 31, 2023

Thanks for the further investigation, @CucaramblaX! To be honest, it would surprise me if this were a new issue in the newest version; circular references in expressions have always caused issues with the render pipeline. You are correct, though, that AE could do more to inform you about what is going on and why the project isn't behaving as you expect.

@marius burkovskj74422166 I'd speculate that what you described (the top-level comp rendering fine until you opened up the underlying pre-comps) might be owed to the circular dependencies @CucaramblaX mentioned. In the project you shared, I do see the jerky/mismatched animation and will check the project in an older version to see if it reproduces there as well.

Cheers,

- John, After Effects Engineering Team