Does animation on twos or ones even matter in 3d animation? Will not there will be automatic keyframes inserted in the animation that make it smooth anyway? In case we want to change the smoothness of animation, we need to change the frame rate, from 24 to 60?
Yes it does. You are thinking of the key frames being inserted, but animating on 2s and 3s has to do with rendered frames. In on 2s you use the same rendered frame twice. So a 24 frame animation is now a 12 frame animation with every frame used twice. This is not the normal for 3D animation and that's one of the reasons spiderman: into the spider verse has such a different feel to it when you watch it. K-POP Demon Hunters goes even crazier, because background is on 1s(normal 3D), the Demon Hunters are on 2s, and the demons are on 3S. As Rumi gets closer to Jinu she starts being on 3s.
Changing the frame rate doesn't always make the animation smoother. A lot of the time it points out the computer's tweening(interpolation). So you end up doing more work to get it smoother.
Hi Yehor,
As Dwayne mentioned - the frame rate can be independent of the 'smoothness'
First let me explain what "Animating on 1s or 2s etc means".
These are terms that come from traditional 2d animation. 100 years ago the frame rate for film was 24 fps (still is btw). This was 24 images every second.
If you are "Animating on 1s" this means 1 drawing every frame (24 drawings per second)
If you are "Animating in 2s" this means 1 drawing every second frame (12 drawings per second and every drawing is shown for 2 frames.)
If you are "Animating on 3s".....well you get the pattern yeah? (each drawing held for 3 frames)
In computer animation you never really "change the frame rate to change the smoothness".
The Frame Rate is one of the first things that is locked and you animate accordingly.
The Frame Rate is set by the final destination of the media or the look you are going for.
When I animate for TV here in Australia it is 25 fps.
Animation for film is 24 fps,
games is generally 30 fps etc (but what about games that run at 60 fps......they are animated at 30 fps and the game engine reads the curve data at subframes to show the in betweens)
A higher frame rate doesn't mean higher quality - it just means more images every second. This could mean 'smoother' but only if it is animated accordingly.
What do I mean by that?
Imagine you've animated something "on 2s". That means you are holding the same image for 2 frames. If you change the frame rate, you are just changing the amount of time the same image is shown - this will not make it smoother - nor should it.
Smoother doesn't mean better either.
24 fps has a specific look and feel to it. We have been watching this frame rate for 100 years and so we are very accustomed to seeing it.
Modern TVs often have 'motion smoothing' which can show more frames per second because it invents frames between the existing ones.
In my opinion this makes "Film" look like "Bad Television" - because the motion is smoother it is changes the look and feel of the media.
What about converting video frame rate post production etc?
We always try to animate to the correct frame rate for the final destination - because changing the frame after a video is complete isn't perfect.
The editing software has to repeat frames (or blend them together) when increasing or decreasing the frame rate.
This changes the spacing and timing of your animation.
Imagine a circle animating from screen left to screen right with even spacing.
Then change the frame rate of the video output from 24 to 30fps. It will need to create 6 frames every second. Most software does this by duplicating every 4th frame.
Now your nice even spacing isn't even anymore - it holds and pops.
Hope that helps.
Thanks for the explanation.
So as far as I understand, the frame rate determines the amount of milliseconds that a single image exists on the screen. The bigger the frame rate, the less time a single image is present on the screen. For example, if the frame rate is 24, we get (1 second/24 frames*1000 milliseconds) 41.67 milliseconds of screen time, however, if the image is animated on twos, it means that a single image is held for 2 frames, meaning that the image is held in total for 83.33 milliseconds. In this case there is no difference between animating on 2s for a 24 fps and animating in 12 fps.
Hypothetically, lets say I animated 16 frame the walk cycle in 24fps. Now, for some reason I need to change the output to 48 fps while preserving the original timing and spacing of the key-frames. Would I be able to achieve that by changing the video output in blender from 24fps to 48fps and simultaneously scaling the key-frames I had in the file by 2, assuming the computer creates perfect in-between frames? Would the same be true if going from 24fps to 12fps and somehow holding those images for 2 frames to simulate the 24fps on 2s look? As far as I understand, this would look different from the original animation and less smooth, on the other hand the original animation would be smoother.
Yep - changing the frame rate and scaling the animation data will always look different from the original animation.
This is because it isn't possible to preserve the spacing correctly.
Here is just a few examples of the many difficulties....
You have keyframes on your key poses - ie the important story telling poses. These are not evenly spaced. Sometimes they are keyed on 1s, sometimes 2s, sometimes...well any arbitrary number of frames. These poses might not have every part of the character keyed and the handle types are all going to be different (auto, aligned, vector etc)
This will affect things when you scale the animation data. The aligned and vector types will keep the same tangents, whereas the auto handles will adjust.
Also if you scale this animation data, the new positions might not fall on a full frame (ie - it could land on a sub frame) and therefore the poses you created will not be rendered......the pose near your key pose will.
Say you are slapping the foot down in a walk over 1 frame (@24fps), then you change to 48 fps (haven't seen that frame rate btw haha). This happens over 2 frames now. The handles between these keyframes are now a problem. Originally you didn't have to worry about them because it was a subframe that wasn't read by the computer. But now that sub frame falls on an integer frame. So those handles control the new inbetween. What where those handles doing? Are the vector, auto, aligned??
The only way to make sure the animation isn't doing anything weird is to adjust them manually.
Sometimes a 1 frame pop might be exactly what you are after - so if you are changing that to 2 frames, you will then need to adjust that animation again.
So what is the solution to all this?
Animate at the correct frame rate.