Render Animation Looking Jittery?

Support Basics & Interface
1

I have a shot in a project that is a simple track up and down of a cello. There are only 2 keyframes on the camera only in the Z channel, start and finish. It is a linear interpolation. And yet the render seems to come out sort of jittery? Stuttery? To be clear, the kind of jittering I’m referring to is not noise, it is rendered at a very high sample count and not denoised. Rather it looks like the frame rate is wrong or something.

It’s rendered in 24fps, the shot doesn’t move fast at all. I’m using Blender 3.0.1. Motion Blur is off. I’ve tried viewing the frames in a couple of different softwares like nuke, natron etc, it just seems to have rendered wrong almost? But I genuinely don’t know what the reason could be. The viewport animation that I do looks fluid, so I’m just confused.

Could anyone help me troubleshoot this? I do not know what the issue could be

2

Hello! Hard to judge without more information. It would be helpful to see the file, or a cut-down version of it, that shows the error.

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3

You’re Right, here is the file.
https://drive.google.com/file/d/1Zisz768hYWqYoMObzyJ6pA7uJ5BCjU6d/view?usp=sharing
There is many linked assets, so for space reasons all you will get is the cello, which is all that matters.

4

True, looks really unsteady. Can’t see a bug though. I guess this shot would actually need a higher frame rate to look good. Maybe other actions would help as well. E.g. lower depth of field, a less geometric background (wallpaper) or maybe even motion blur …

5

By the way, your render settings seem a bit unusual to me. you have no noise threshold enabled and a sample rate of 10240. that must take forever to render …

6

It is usually high but it’s for a demo reel, so it’s just about needed for fully clean shots. I was hoping for a bug or something, because I believe you are right that a higher frame rate seems needed. Maybe motion blur can help too, but I’ll have to test it. Either way I needed to confirm there is no bug, and there seems to be none. Thanks for looking!!

7

You’re welcome! Slowing down the camera movement might also help, if that’s an acceptable option for you…

8

Unfortunately I edited my previz to music, so I need to keep this pace. I just didn’t anticipate this issue, it didn’t seem like a problem shot. My own fault I’m afraid :frowning:

9

What you are seeing could be due to a mismatch between your video frame rate and your monitor refresh rate. A 24fps video played on a 60Hz monitor won’t playback perfectly smoothly, some scenes/shots will show the mismatch more than others.

From your .blend file, it looks like you’re saving the render as .png files and creating a video from them. Try creating a test video at a frame rate that your monitor should be better with (e.g. for a monitor running at 60hz, try a 30fps video) and see if it looks smoother.

I know this won’t fix the problem but it may show you where the problem is.

2 Likes
10

Setting it to 30fps seems to alleviate it just a bit perhaps? Setting to 50fps perhaps even more, but neither really fully solve it. I’m just so surprised that just a small movement causes such a mismatch. I guess this may have been obvious to someone who knows more about cameras, but it seems almost bizarre to me. Really it seems the only true solutions is to slow the shot down by changing keyframes.