[jakelazaroff]

We do this in cartoons as well. Check out this Spider-Verse animator breaking down a shot of Gwen drumming. [1] If you look at individual frames, there are all sorts of details that make no logical sense. In one frame, she actually has three hands! But it looks great if you see it in motion.

[1] https://xcancel.com/hf_rosa/status/1089675426312552449

[jchw]

That is exactly what I'm talking about, though. This is not what is happening with buggy computer UI animations: these are not carefully crafted to look better in motion, they're actually only considered acceptable because it's kind of difficult to see the mistakes in the animation. Whereas cartoon animating, you could argue the details don't make logical sense, but that's only to someone who doesn't understand the principles of animation. You can't explain away glitchy weird UI transitions this way because they're pretty much universally not intentional. They're usually just taking the technical path of least resistance.

[wtallis]

I think there's also a major difference between the kind of weird intermediate frames that are acceptable for a highly-stylized cartoon at 24FPS and the kind of intermediate frames that are acceptable for a UI running at 120FPS.

[jakelazaroff]

No one is defending outright buggy animations. OP is just saying the idea that every frame should make logical sense on its own ignores how animation actually works (and they're correct).

[fenomas]

That's not what TFA is about though.

Look at the youtube example - it has two pieces of UI animating from from a start point to an end point, and the paths are such that they momentarily overlap. There's nothing buggy or janky about it in motion; TFA is just saying that if you ignore the motion and take a screenshot mid-transition it looks odd. Same complaint as what GP describes, and silly for the same reasons.

[jchw]

It's what I personally took away from it. I was also someone who had the same feeling when I first heard Wayland's "every frame is perfect" mentality. I thought, "This is probably a good idea on multiple levels."

I agree the YouTube example isn't the worst one, but also at the same time, I don't agree with you that there is nothing buggy or janky about it.

https://tonsky.me/blog/every-frame-perfect/[e-mail]?t=...

There is no logical reason for there to be two copies of the video rendered at once. The video is literally resizing into position, while all of the UI elements shift around it. Why would there be more than one copy of the thing that is resizing?

I will relent on only one thing: "If I take a screenshot of your app at any moment, it must make sense" is too strong of a statement on its own. The context that it is a screenshot of an animation is important, just like cartoon inbetween frames. However, I think if you're being generous with interpretation you can allow this to be implied.

[fenomas]

I see what you're getting at, but I think you're focusing on the incidental. An animation is good if it's clear and intuitive in motion. It may often be the case that good animations also look nice in a screenshot halfway through, but (a) they don't always, and (b) working well in motion is obviously the more important of the two goals.

As such it makes no sense to worry about the latter thing - it's not a signal whether the animation is good or not.

[Terr_]

Or "squash and stretch" [0] frames cartoons and 3D modeling, where people prefer the final result even though individual frames can be grotesque.

That said, I think it's fair to hold most practical UIs to a different standard. Prioritizing amusement leads to a lot of strange non-ergonomic places.

[0] https://en.wikipedia.org/wiki/Squash_and_stretch

[LinAGKar]

Of course, even real life can look quite grotesque if you look at it in slow motion, as things get deformed by forces [0], so it makes sense animations would need to simulate that.

[0] https://youtu.be/On1CsbTwlDs?si=0UZADk-jtJvOQGww&t=33

[numpad0]

GGP's point is that broken in-between frames are everywhere, in films and animations, and this is a total nothingburger.

GP's point is that those frames aren't broken, but they're intentional and calculated, and so they're not even relevant here.

[bmurphy1976]

Oh boy, I wouldn't use Spider-verse animation as an example. I personally hate it. When I saw the first movie I thought something was wrong and asked the staff if I had mistakenly been put in a 3D movie without the 3D glasses.

Impressive and creative yes. Viewable? Not to me.