This may be a silly question, and it may be worded incorrectly but I'm not too familiar with expressions.
I'm trying to set the value of an effect to sync with audio I've converted to keyframes.
However, I want the value of the effect to continue adding whatever the new audio keyframe is.
Is this possible?
The After Effects expression engine works in current time only so you have to be careful not to set up a Lookback loop that is recursive because things will slow down to a crawl with each frame requiring a look back at all previous frames. The approach in the link provided by Mylenium and authored by Dan Ebberts is your best chance of getting these kinds of calculations to work without bringing AE to its knees.