Opacity Pickwhip to Audio Keyframes

[Skyler25680786b7dv]

Hey guys I am trying to create a neon box around a subject and have the glow flicker to a certain db range of the audio file. I've done this for scale before and the expression is relatively easy to set a thresh hold but opacity doesn't seem to work as friendly. I have got it semi working but I have no expression to control the opacity min/max and no expression to control which frequency the opacity reacts to. Any help would be greatly appreciated. I just simply want the glow to come in and out to a certain range of the beat.

Not great with expressions so keep that in mind in case it's really advanced lol. Still learning the expressions side and how the coding works.

Thanks in advance for any help!

[Mylenium · Accepted solution]

You cannot extract specific frequencies with expressions, so this alone makes no sense. You have to process the audio in a respective program and save a version of it to be used as the reference for your expressions. To some degree you may be able to do that in AE with the very limited audio effects in a pre-composition. The rest isn't clear. Since scale and opacity basically work the same, you should not have any issues to feed the same ranges into your code, but perhaps there needs to be some tweaking or a linear() function in there to remap the ranges. Either way, you need to provide a better explanation of what you want to achieve rather than just describing the problem.

Mylenium

[Skyler25680786b7dv]

Mylenium thanks for the quick reply. Let me see if i can clear up what I'm trying to do a little better. I'll attach a screenshot to go with it.

I have an image with a subject in the middle of the screen. There is a neon box around him that I am trying to get to flicker and I want the flicker to follow the beat of the song. I assumed inserting a layer with a brighter glow and then pickwhiping the opacity to the audio keyframes would be the easiest method for this. Not sure if I'm missing a step but check out the screenshots to get a better idea of what I'm trying to do.

I am also getting some sort of dotted line effect on the glow at this current stage. It's like the whole shape isn't being effected by the glow and just certain areas of the line. Not sure if thats due to an expression eroor or something else but let me know if you have any suggestions or direction for me.

[Dan Ebberts · Accepted solution]

You may not have the audio range (audioMin and audioMax) set up to give you the best effect. I notice from your screen cap that the slider value is 14.81 which would peg the opacity at 100%. It would be helpful to see the actual range of the audio keyframes in the graph editor.

[Skyler25680786b7dv]

This definitely helped lol. I went into the graph and just kinda pulled all the lower keyframes down and raised the all the higher ones to 100 and it looks great. I originally wanted it to be perfectly on beat but I think the inconsistency is more natural for a neon look anyways! Thanks for the help. I'm sure there is a much easiert way of doing this but I will have to do some more research on how to use expressions and learn how the coding works and see if I can come up with an easier method for others who just want neon glows to flicker to audio keyframes lol. Appreciate the help tho. This community is great!

[Warren Heaton]

Have you tried this approach?

https://youtu.be/5UkHJWcPVCo?si=paDnS6h8w-wwfIgN

It uses Keyframe Assistant > Convert Audio to Keyframes and then links the Expression pick-whip to the results.

[Skyler25680786b7dv]

Hey Warren, Yes I have the audio keyframes already created. It's more just what expression to use to get the opacity to react better to the beat.