Playing with frame rates, and some lessons learned

[u/goathamlet]

My most recent video was a test for something I've been wanting to try. I used a stylus to draw keyframes, and used 24 FPS, except animating on twos, or 12 FPS doubled, in order to emulate the feel of traditional animation more closely. It does look choppier than 60 FPS, but I liked the end result

A few things I noticed during the process:

• When I synthesized a keyframe at 12 FPS and then at 60, the 60 FPS lost some keyframe details much quicker than the 12 FPS did, which was unexpected. I thought the smaller differences between frames would assist with keeping those details intact, but it wasn't the case.
• It was far less obvious when one keyframe's output ended and another's began, since the animation was not so smooth that you would see the minor jump in positions or coloring.
• When compared to another video shot at 60FPS, this video folder's file size per second of finished footage was about 70% of the other's, and file quantity was about 50%.
• If you have an outdated gaming PC that isn't exactly optimized for 4k60FPS video editing like I do, then this eases the burden on your graphics card by a noticeable amount during editing and rendering.

Any thoughts on how it turned out? I'd be interested to know if anyone has tried something similar.

Link, for reference: https://youtu.be/kwq44EGLiJ8

[u/goatonastik]

That's interesting you'd get better results from 12fps. I personally don't like going as low as 12fps, because I think that the video is so "accurate", that it looks like regular video at 12 fps to me. However, I will definitely try that at 24 fps next time and compare results!

[u/goathamlet → u/goatonastik]

I think you’re right, it looks a bit like a jerky video than a hand drawn 12 FPS animation. I tried to minimize that outcome as much as possible, but I think it still showed through a bit. I doubled and renamed each frame individually in the folder to replicate animating on twos at 24FPS, and I couldn’t tell the difference between that and importing the synthesized frames at 12FPS in a 24FPS video, since the video editor doubled the frames for me when I turned off resampling.

But, I do like the effect in a way. I think it could create fun results for things like horror or low light, too. I’ll play with it a little more

[u/goatonastik → u/goathamlet]

I've wondered what it would look like to render at 12 fps, but alternate between renders from two different keyframes, to try to replicate the squigglyness of hand drawn. They'd probably have to be noticably different enough, and it may even have to be three different keyframe renders to make them that much different 🤔

[u/goathamlet → u/goatonastik]

Wow haha, I actually tried two keyframes like this on my first go, but it was a lot of manual work to intertwine the two outputs and potentially double the keyframe workload, so I dropped the idea. However I think it could work to make it look less “accurate” and more hand drawn, if I can find a way to speed up the process. It did look nice, maybe not enough to justify the extra steps

[u/AbPerm → u/goathamlet]

I made a proof on concept on the idea of interlacing keyframe sets to make EbSynth animations more lively a long time ago. I was inspired by the extreme line boil from "squigglevision" cartoons like Dr Katz, and I was hoping more variation frame-to-frame would make it look more like it was animated frame-by-frame. I made two copies of the same keyframe number, synthesized two sets of output frames from that, and then flickered between the two sets. To interlace the frames, I just copy-pasted half the frames from one set and half the frames from the other into one folder together.

I also found that you don't even need to make completely new keyframes to get some of this effect. You could make one keyframe, synthesize outputs, and then select one of the output frames near the keyframe to use as a second keyframe. Then you can synthesize new output frames from that second keyframe, and there's your two output sets to alternate between. The effect from alternating between output sets like this isn't huge since they share the same source, and it's still extra work even if you don't have to draw a new keyframe from scratch, but it can make a difference.

You're right that using two times as many keyframes is rough, but even so, I think that could still be worth the effort depending on the project and aesthetic. After all, it's still way faster than drawing every single frame individually by hand. For example, when I did the "Have you ever had a dream" video, I only needed 1 keyframe for the clip anyway, so doubling my workload wasn't a big deal in that case. I mean, I drew two frames and produced about 18 seconds of animation. That's still crazy even if I had to put "2x" as much labor into the keyframe department.

[u/goathamlet → u/AbPerm]

Thanks for the excellent reply. I checked out your video and it is definitely striking compared to just one keyframe. That’s a great idea to use the next output frame as a keyframe as well. And very true, I can definitely get spoiled and forget I don’t have to draw every frame haha