Creative Communities of the World Forums

The peer to peer support community for media production professionals.

Activity Forums Adobe After Effects Expressions Expression that triggers on a new frame in a sequence

  • Expression that triggers on a new frame in a sequence

    Posted by Malcolm Sutherland on November 21, 2022 at 10:33 pm

    I’m wondering if its possible to create an expression that could detect when a new frame appears in a sequence / precomp. For example, with an animated sequence over a paper background, whenever a new image appears in the animated sequence the paper texture would be moved. I have no idea how to achieve this or if its possible.
    Thanks !!

    Malcolm Sutherland replied 1 year ago 2 Members · 2 Replies
  • 2 Replies
  • Dan Ebberts

    November 21, 2022 at 11:02 pm

    The only tool expressions might have for something like that would be sampleImage(), but it would be ridiculously slow. You could do it using the plugin API, but that’s a steep learning curve. You’d probably be better off marking such trigger points by hand with layer markers or keyframes and have the expression triggered that way.

  • Malcolm Sutherland

    November 22, 2022 at 12:31 pm

    Thanks! Yeah thats roughly how I have been doing it, but its time consuming and if there are any changes to the sequence or precomp, the triggered “effect” keyframes need to be repositioned.
    A thought: Is it possible to parent a keyframe’s position in time ? In the example I gave above, if I had a keyframe at the start of each image that was parented to a keyframe in the “effect” layer (using it for its timecode)? that might take out a step at least. (…if that makes any sense)

We use anonymous cookies to give you the best experience we can.
Our Privacy policy | GDPR Policy