why the rotation is not smooth?

[ssu69113334]

video

[_keyframer]

I see the rotation is very jerky but only lasts about 1 second. How many frames is the animation for the rotation? What is your frame rate set to?

[ssu69113334]

24 frame rate. the baloon goes down smoothly, but when i add rotation - it becames jerky

[ssu69113334]

https://yadi.sk/i/QBmnmTa-TX4frg

better video

[_keyframer]

For some reason I just can't get that video to play. It shows a static screen, then a loading animation and then nothing. Sometimes if you have a little rotation over several frames, the motion can seem jerky. This asset being a bitmap may also be the reason for the jerkiness. Have you tried adding some easing to the tween span? Did you use Classic Tween or Motion Tween?

[ssu69113334]

I tried both classic and motion. And it is with easing. It is for about 50 frames in each side

[_keyframer]

Is it possible for you to share the actual FLA? I may need to take a look at the timeline itself.

[ssu69113334]

sure- appresiate help - https://yadi.sk/d/67K3cCiZvHzrVA

[ssu69113334]

replaced bitmap with vector rectangle - the same

[_keyframer]

Okay. You are not doing anything wrong. I have duplicated this using your bitmap asset. I then edited the asset in Photoshop by cropping out the transparent background as much as possible to make the image smaller. It still is jerky. I tried no easing, and a custom ease as well. Still jerky. I tried 30 fps but it's only slightly better. I then drew a vector rectangle roughly the same size and rotated it the same way across the same number of frames - it was also jerky. I also tried selecting the tween span and in Properties panel deselecting "Snap" and "Scale". Still jerky. I'm going to log this with the engineering team to see if it is truly a bug. I would think it should be smoother since doing the same type of animation in say After Effects yields smoother results. I know they are different applications but this is too visually a flaw in my eyes.

[ssu69113334]

thanks... so there`s nothing I can do... cancel rotation for now

[_keyframer]

Since this looks like a banner ad, I am assuming you can't change the frame rate. But if you can, try going from 24 to 30fps. And then try and play with the number of frames between keyframes in the tween span. I would suggest fewer frames perhaps. But yeah, unfortunately for some reason, AnCC is producing a motion that suggests some sort of snapping is turned on but I think it's something that the engineering team needs to look into. I'm going to play around more with it and if I solve it I will let you know.

[ssu69113334]

thanks. its for video, not banner

[_keyframer]

Okay - I think I found a way - I rotated the asset more than what you had and it looks much smoother. I think there's some kind of delicate balance between frame rate, number of frames and the distance an asset is rotated when it comes to how smooth the animation will be.

Download my FLA
JerkyTween.fla

[_keyframer]

Also, maybe have the asset start on the first frame rotated to the left more instead of no angle. That may also add more rotation thereby making it smoother.

[ssu69113334]

I can’t achieve a satisfactory result anyway

[JoãoCésar]

Hi.

Your bitmaps are very large in both dimensions and file size.

Also you're using a very short rotation.

If you change this you're gonna probably see a performance improvement.

Regards,

JC

[n. tilcheff · Accepted solution]

Hi mate,

Plain and simple: Flash / Animate cannot Classic / Motion tween small rotations over longer spans of frames.

This has been a known issue for decades.

In your case you have 0° to -3.5° spanned over 50 frames.

If you use classic tween instead and convert all frames to keyframes you can check the rotation values for each frame and it all will become quite obvious.

You can try manually setting values such as -0.1° or -0.2° and you'll see that they get rounded to zero.

Flash just can't do this kind of thing.

It has nothing to do with your frame rate or the size of bitmaps as the ACPs have suggested. Even if you had just a vector rectangle you would face the same problem.

The problem is mathematical and how Flash rounds and calculates rotations. -3.5° over 50 frames just does not give it enogh increments to work with and that is why you end up with a jerky movement that is literally one step every 6 frames or so.

This smooth rotation just cannot be done with a Classic or Motion tween.

Now here is what you CAN do: You break apart the bitmap and then Shape Tween it inside your container.

Shape Tweens don't have this problem and everything works as smoothly as you need it.

Here is your fixed file: https://drive.google.com/file/d/1aNKS6FSYldy-aIxek9-_a7qekxvf5Vj7/view?usp=sharing

Good luck!

[JoãoCésar]

Hi.

Very good answer!

Regards,

JC

[ssu69113334]

WOW! thanks a lot! you are a magician!

[n. tilcheff]

You're most welcome, mate!

[_keyframer]

Break apart and shape tween a bitmap? What kind of witchcraft is this? Great idea!