5 Replies Latest reply on Oct 22, 2013 11:10 AM by sinious

    Need help with jerky animation in Flash CC

    laurel2013

      Hello,

      I'm creating an animation of a planet orbiting the sun and it is stuttering a little bit no matter what I try.  I'm working in Flash CC, the animation is done with a custom ease and only 2 keyframes (one at the slowest point and one at the fastest).  The end result has to be .mp4 so I am exporting as video.  But even the swf is a little jerky.  My frame rate is 29.97.  The animation path is oval in shape (using an oval guide path which the planet follows), the planet is small, maybe 6 mm across,  and the planet's speed varies as it orbits the sun (thus the custom ease).  The number of frames in the animation is 202, that's how long it takes for the planet to complete one rotation.  That anim is then looped in the movie as a graphic.

       

      thanks in advance for any help you can give.  

        • 1. Re: Need help with jerky animation in Flash CC
          sinious Most Valuable Participant

          How large is the orbit itself (pixels)? You're only taking around 6.7 seconds to complete the orbit. That's pretty fast for an orbit considering the easing will eat away at it.

          • 2. Re: Need help with jerky animation in Flash CC
            laurel2013 Level 1

            Here is a screenshot:  the movie is 1280 x 720 and the orbit path is 633.15 x 446.65Screen shot 2013-10-22 at 10.14.02 AM.png

            • 3. Re: Need help with jerky animation in Flash CC
              sinious Most Valuable Participant

              With that circumference, in linear (no easing) you're talking about 1720 pixels worth of distance to travel over 6.7 seconds. That's around 250px per second or around 8.5px per frame. Now that isn't considering the easing which is going to eat away at the number of available moves given the amount of time.

               

              Moving 8.5px per movement linearly would look somewhat boggy. The only thing you can do in this instance to make it feel smoother is give it more FPS or a longer duration. Either will cut that ~8.5px down to a smaller movement and will make it appear smoother.

               

              What do you find jerky about it? The faster motion opposite any easing that slows down?

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              • 4. Re: Need help with jerky animation in Flash CC
                laurel2013 Level 1

                Thanks for explaining the division of frames over the course of the orbit, that makes sense to me.  The movie seems to have random mini-stutters as it plays back. It doesn't always happen in the same location.  Thank you so much for all your tips and help on this issue.

                • 5. Re: Need help with jerky animation in Flash CC
                  sinious Most Valuable Participant

                  Here would be a similar example, linear versus an ease tossed in. I made an oval similar to yours (633px by 446px) and just used it as a guide:

                   

                  sphereease.jpg

                   

                  Here's some videos showing the movement I get per frame. You can even see Flash Pro (CS6 in this case) exporting some odd frame choices. For example right before the 5 second mark the circle jumps 2 movements and stays in place for an extra frame (easy to see stepping through it using arrows and Quicktime player). It does this consistently even when using "None" for Quicktime compression, or using a codec.

                   

                  Here's some video examples (30FPS over 202 frames, 6.7 seconds):

                   

                  Linear Movement

                   

                  -60 to 60 ease at the opposite side

                  (Source MOV (Animation codec @ 85 quality) to verify MP4 is the same)

                   

                  I imagine your results are the same. It's just too much movement for to little time to really get it to play back smooth. Double the time and you'll cut that in half and I think you'll be happier. Increasing FPS beyond 30 might not be a good idea as playback will start to become machine dependant at that resolution and it could bog even worse.

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