What's the secret to creating silky smooth animations ?

[JezUK]

I don't get asked to do very many animations but have got a couple coming up over the next 2 months - but whenever I have created them they never appear as silky smooth as others I have seen and how I'd like mine.

For example, creating a walkthrough, through a building, at walking speed.... I'm aware of how fast the camera is travelling (walking speed), so if I render out 30fps, why do I still see 'video tears' ?

I've heard of the trick to render out at a higher frame per second (what fps I don't know) and playback at 30fps, would that fix things ?

Is that the secret cure ?

Also, I've heard to use Motion Blur.

But taking a look at some of the animation content on NVidia's website - they're as smooth playing and flowing as I'd like - no visible amounts of blur, so what gives ?

https://www.nvidia.com/en-us/geforce...geforce-store/

Any guidance please ?

Thanks.

[Companioncube]

that animation on the nvidia site website has motion blur, you need motion blur.

[delineator]

For example, creating a walkthrough, through a building, at walking speed.... I'm aware of how fast the camera is travelling (walking speed), so if I render out 30fps, why do I still see 'video tears' ?

No expert here, BUT 60fps would help. Matching refresh rate will make it feel silkier smooth, but obviously at the cost of render time for 2x frames. However, you then dip into "soap opera" territory (keep in mind films are still effectively 24fps and people HATED The Hobbit in HFR @ 48fps). I'm not sure why tearing would occur, especially with a constant frame rate, but like in gaming, 60fps will feel better than 30.

Just messing around I've had some luck interpolating frames up to 60 using a 30fps animation source via premiere (I think I used frame interpolation, but would have to check it against optical flow). Its a quick an cheap fix, so try it out and see for yourself.

[Ihno]

I tested this once.
This "perfectly smooth" cg cam movements are a problem. It's easy to spot lower framerates if everything is predictable.
Some speeds are worse than others.
I read about a 7 second rule which claims if something needs 7 seconds to pass the screen it will be quite smooth.
MB is also very important.
And a higher framerate can help.
But I didn't wanted to render twice as many frames or even more.
I noticed that I barely see such jittering in real camera footage.
A big part of the reason seems to be the imperfection of real cam paths.
Even with sliders or dolly their is still a little extra movement.
Here is my test.
It's a red box that moves in front of a still cam (could also be the other way around)
It's a scenario where the jittering is very obvious and I think it wouldn't be that bad in most production cases.

25fps
150? Shutter angle:
https://drive.google.com/open?id=1wT...aAGVVcpHk6O8V5
180? Shutter angle:
https://drive.google.com/open?id=1jB...Ci_PJ3D1SSTquX
250? Shutter angle:
https://drive.google.com/open?id=1-6...1SrIQPcsRyCIwT

30fps: (unfortunatly just one)
180? Shutter angle:
https://drive.google.com/open?id=1tL...Mb4za6zotxnuu_



Then I added a (very)little bit of random movement to the camera and at least to my eyes the effect is way less noticeable for most speeds:
25fps
180?Shutter angle:
https://drive.google.com/open?id=1oo...4VlqmCPiic-GiS
250?Shutter angle:
https://drive.google.com/open?id=1z-...EIRjWLVoB1k5fd


Unfortunately I haven't had the time to make more videos of this and see if I can make the jittering disappear completely but I think it depends on the fps the mb duration (more is smoother) and the movement itself.
For some speeds one might need to find the sweet spot between those.

[Vizioen]

Very interesting Ihno. Nice tests. But the jittering is very apparent in all cases under 7-8 seconds here.

[Ihno]

Yes its indeed a very interesting topic. I think I have to come back to this soon.

[cheerioboy]

Those tests feel like they're messing with my eyes. If I don't look directly at the red object it seems smooth - but when I'm tracking with my eye it seems to jitter...

[Ihno]

Those tests feel like they're messing with my eyes. If I don't look directly at the red object it seems smooth - but when I'm tracking with my eye it seems to jitter...

Yes that might be the most important thing.
Its maybe something you need to consider for the whole animation. In theory a rule could be:
The focus point of the observer(you / your client) should have the movement speed of the 7-8 sec objects.
The rest of the scene can move in different speeds (seen as 2d movement) it isn't important because if you don't try to spot it it'll be quite smooth.
Consider a different mb duration if you have to break that rule.

But it's too early to say anything.
I'm afraid I'll even have to question that scene....