Latest post Wed, Jun 7 2023 12:08 PM by Cutyes. 3 replies.
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  • Sun, Jun 4 2023 8:47 AM

    • Camillo
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    Trying to animate a sequence of images with alpha above static video track

    Hello,

    I have an edited sequence on V1.

    On V2 I have 3 images with alpha. They depict phases of flight of a bird. I have them stand shortly and have short dissolves between them. This is on a loop made by repeating the sequence. The bird is on the fg, the V1 sequence in the bg.

    I thought I can collapse the bird sequence to be able to keyframe animate it over the background. Whenever I move the birds, I move a composite of the bird and the bg over the bg.

    How can I set up the timeline to achieve what I need? Many thanks in advance!!

    MacBookPro 15-inch, late 2013 MacBook Air M1 16GB/1TB MC 2018.12.2 MC 2022.10 [view my complete system specs]
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  • Mon, Jun 5 2023 7:03 AM In reply to

    • MikeyB
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    Re: Trying to animate a sequence of images with alpha above static video track

    Unfortunately you've hit one of the limitations of the way Avid's effects system works. The workaround for this is a bit cumbersome...

    First you need to make a Video Mixdown of the foreground image of the bird (disable the b/g on V1, mark in & out around the bird on V2 then Timeline menu/video Mixdown). Put the mixdown on V3 in your timeline.

    Then you need to make a mixdown of the Alphas. Step into each matte key, mark i/o on the Alpha, then alt/c to copy the alpha to the Source Monitor, then overwrite it back onto V4. Add your dissolves between the Alpha clips.

    Mixdown the Alpha and edit it back in place of the alpha clips.

    Then add a Matte Key effect to the Alpha.

    Animate.

    Enjoy!

    2021 MacBook Pro 16" (M1 Max 32GB), 2019 iMac 27" (8-core i9, 40GB) [view my complete system specs]
  • Tue, Jun 6 2023 8:06 AM In reply to

    • Camillo
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    Re: Trying to animate a sequence of images with alpha above static video track

    A little tedious, but at least it works. Thanks for letting me know how to achieve it! Will give it a try and let you know how it turned out.

    MacBookPro 15-inch, late 2013 MacBook Air M1 16GB/1TB MC 2018.12.2 MC 2022.10 [view my complete system specs]
  • Wed, Jun 7 2023 12:08 PM In reply to

    • Cutyes
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    Re: Trying to animate a sequence of images with alpha above static video track

    Similar to what MikeyB wrote but without mixdowns, hence with the opportunity to alter and batch re-import the graphics or to make changes to your edit:

     

    Assuming your BG is on V1…

     

    1) Edit one of each of the three phases into the timeline (V2)

    2) Step inside the first clip

    3) Of the two clips (matte on V3, fill on V2) that you see in there, [ALT]+[CMD]+[C] the matte to the source monitor

    4) Step back outside

    5) Edit the matte above the original clip

    6) Remove the „effect“ from the original clip on V2; that will strip off the matte and leave you with the fill only

    7) Repeat 2-6 for the other two clips

     

    Now edit, loop and blend those packages of matte (V3) and fill (V2) up to the desired length of your animation.

     

    Once you are done with that, collapse V3; meaning one single collapse, from beginning to end, but leaving V1 and V2 as they are.

     

    After that ALT-drag a matte key (from the effect palette) onto the collapse.

     

    To keep things tidy you could remove the collapse, that is now inside the matte key, after that. It is no longer needed.

     

    If all went right, you should now be able to animate the bird via the matte key.

     

    Be aware, there is a downside regarding dissolves: with matte and fill treated separately, the outcome of dissolves will be different from dissolves on graphics with integrated alpha channel. In your case it might be okay because the dissolves sound to be very short. If not - and if no dissolves is not an option - maybe create or ask for one or two more phases or try to fake some motion blur.

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