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Activity Forums Adobe After Effects Expressions Expression edge object?

  • Tom Morton

    October 13, 2023 at 7:34 pm

    Definitely is something that could be controlled by expressions, but feel I’d need a bit more info. Is the object in the middle something that will change or will it always be the “A”? And what sort of animations is applied to it?

  • Tom Morton

    October 13, 2023 at 8:18 pm

    Actually you don’t need any expressions. Nest the animated object with a black background. Apply a mosic effect with 1 width and 1080 height (or height of comp). Then apply a curves effect to make everything not pure black into white.


  • Rafael

    October 13, 2023 at 8:23 pm

    The object in the center would change. The alpha channel should be defining it. I recall many moons ago, Dan Ebbert had some expression about “magnet or repulsion” expressions. I was wondering if a simple rectangle with the anchor point ant the bottom could have the Y axis fluctuate with the scale value. But I am not great at expressions…

  • Tom Morton

    October 13, 2023 at 9:48 pm

    Check out my example above, this will achieve what you want without any expressions which will be much faster and still 100% accurate.

    If you specially need expressions for any reason there’s a couple of options but in this case I would avoid as it can be done more easily with built in effects. The example above will work fine for an alpha or color channel.

    The mosaic effect averages all the pixels in the entire row, and curves effect takes any color that isn’t pure black and makes it white. You can use this strategy in different ways but it will always respond to the animated object, in my case the abc text.

  • Rafael

    October 20, 2023 at 12:27 am

    OMG, this is brilliant. You’re a genius! I thought something like that but I couldn’t voice it. The Curve is the key.

    Thank you so much 🙏

  • Brie Clayton

    October 20, 2023 at 1:09 am

    Thank you for your brilliant solve, Tom!

  • Tom Morton

    October 20, 2023 at 6:18 am

    That’s ok guys! 🙂

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