Animate in 24fps with 12fps appearance (with a twist)

[Nick Made]

Hello,

The goal is to have a 24fps animation appear as 12fps (double frames / animate on 2s). Example: a box moves from point A to B with simple Position keyframes, but the output is a box moving at 12fps.

I'm integrating this with a web script with limited AE features support so I can't:

• use a 12fps pre-comp nested in a 24fps with Preserve nested framerate advanced option
• use the Posterize Effect
• only use an expression with PosterizeTime
• scripts that don't return actual keyframes and native AE functionality

The closest flow I have is to use this expression, e.g. on the Position property:

animateon=2; framerate=(1/thisComp.frameDuration)/animateon; posterizeTime(framerate); value;

And then convert those with Convert Expression to Keyframes, but that returns a keyframe for every frame, whether it needs to or not.

I tried jdSmartBaker to reduce the keyframes, which mostly works very well but it chokes on certain properties like Rotation (for me anyway).

This process is cumbersome. Ideally, I would like everything (the entire comp) to be hard set double frames.

FYI, I am animating shape layers and won't be working with 'footage'.

Phew. Does anyone have any suggestions?

Thanks!

Nick

[Mylenium]

Whjat stops you animating at 12 FPS to begin with and only setting the preview framerate diffewrently? Conversely, since your intended target output is code, anyway, what stops you from editingt the base framerate in your SVG or HTML canvas after the fact? Seems to me you are overcomplicating this and not seeing the obvious.

Mylenium

[Rick Gerard]

Way over complicating the problem. Set your comp frame rate to 12 and animate away unless you need to mix frame rates for some reason.

What do you mean when you say you are integrating with a web script? Are you trying to create an animated SVG? If all you are doing is moving shape layers around the Aminate is the tool you should be using. If you have to use AE there should be no limitations on frame rate for your export.

[Nick Made]

Hi, Mylenium and Rick Gerard    thanks for replying.

It's not an overcomplication from my perspective.

I would like to potentially use 24fps because if I need to I can animate on 2s for normal movement, and on 1s for fast movement, I have that option. I can't do that solely with 12fps comp framerate but it would be easier, of course. Also, 1/8th timing is easier to land on a 4 frame — with 12fps, it would be 1.5f.

The main delivery is SVG animation but I will be using AE with Lottie. The control over framerate on the code end is questionable from what I understand, which may be another obstacle in of itself. The output will also likely be in video format for YouTube but that's a secondary priority.

The other consideration is certain objects will have different animation approaches. A circle bouncing up and down would be easier to set a couple keyframes, however, the splash of a puddle would be drawn by hand and each shape change (of the water) would be its own keyframe.

I hope that makes more sense.

Thanks!

[Rick Gerard]

Time is divided into frames and keyframes are placed in time, not frames. If you have a 24 fps comp and you change the frame rate to 12fps the position in time of the keyframes will not change, but the start and end of each frame will change. Your example:

I would like to potentially use 24fps because if I need to I can animate on 2s for normal movement, and on 1s for fast movement, I have that option. I can't do that solely with 12fps comp framerate but it would be easier, of course. Also, 1/8th timing is easier to land on a 4 frame — with 12fps, it would be 1.5f.

Makes no sense at all because keyframes are placed relative to time, not frames, and frames per second can be number, 23.673859238347 so there is no guarantee that a keyframe at  1/2 second will be placed at the beginning of the frame that is closest to 1/2 second. Your numbers are also off. 1/8 speed in a 24 fps comp falls happens at the end of frame 3, the start of frame 4 but in a 22 fps comp the keyframe would fall in the middle of frame 2, which is 1.5 and you can't make a frame move in the middle.

Do you see where I'm going? Check out these screenshots:

There's a keyframe at 1:03 or 1 and 1/8 second. We switch the frame rate to 12 and:

The keyframe is at 1:02 and 1/2 frames or 1 and 1/8 second. The layer is going to get to that position 1/16 of a second sooner than it would in a 24 fps comp but it has to because the timing of the frame can't change. Visually there is a difference in the look of the motion because of the lower frame rate, but there is no difference in timing that you can do anything about.

Like I said before: if you want the look of 12 fps motion then set your comp frame rate to 12 fps. If you want the look of 60 fps motion set your comp to 60 fps. The timing will be the same, only the quality, feel, look or whatever you want to call it will change. All of that monkeying around with posting time, nesting compositions with different frame rates and expressions is a complete waste of time unless you want to have one layer to have the look and feel of 24 fps motion and the other to have the look and feel of 12.

[Nick Made]

I'm not entirely sure we're talking about the same thing but let's find out. There's footage on Vimeo of animations at 24fps, with both animation landing on 2's and on 1s.

If I set my comp to 12fps, where do I add in more data/information/keyframes for in-between animation? 12 frames in a second is 12 frames total available, right?

If I have 24 frames available per second, I could add in more in-betweens to convey smoother/faster movement, right?

If I have a 24 framerate, and animate on 2's, I can minimize the work needed, e.g. a head-turning. But if I need to add additional frames to animate on 1s, how I can do that on a 12 frame rate if the sequence happens to be 13,15,18,19,20 frames in total necessary?

Maybe someone has 2d/cel animation experience that can chime in? I'm not dealing with raster-based video, so my approach inherently will have to be different and that's what I was looking for on here.

[Rick Gerard]

Sorry, you still don’t have it right. If you animate from position one the position to have 12 frames per second and each frame moves the layer 10 frames forward, then you change the frame rate to 24 frames per second it will still take exactly the same amount of time to get from position 1 to 2 but the position will change at the rate of five pixela pee frame.

On the other hand if you want action to change direction precisely at two seconds, it doesn’t matter what the frame rate is, the action will change direction when the closest possible frame is it two seconds. The actual keyframe could end up at the beginning middle, or last 10th of a frame because the length of the frame determines the accuracy of when that direction change happens.

[Dave_LaRonde]

The main delivery is SVG animation but I will be using AE with Lottie. The control over framerate on the code end is questionable from what I understand, which may be another obstacle in of itself. The output will also likely be in video format for YouTube but that's a secondary priority.

The other consideration is certain objects will have different animation approaches. A circle bouncing up and down would be easier to set a couple keyframes, however, the splash of a puddle would be drawn by hand and each shape change (of the water) would be its own keyframe.

Even after all that, there is still no good reason to approach this project the way you are doing it.

[Nick Made]

If you have an approach, that's 100% what I'm hoping to learn. Would you mind sharing?

[Dave_LaRonde]

Sorry, but I don't have one.  I wouldn't do it that way.

[LL_Cool_Dave]

Sorry, wrong entry