Simple Trigger Fade - After Effects Expression by Animoplex

SimpleTriggerFade.jsx

// Simple Trigger Fade - Created by Animoplex: www.animoplex.com
// Repeat a fade animation multiple times using markers to trigger the animation.
// Full Tutorial: https://www.youtube.com/watch?v=B_3XS2-VWOM

fadeFrames = 30; m = 0; t = time;
if (marker.numKeys > 0) {
    m = marker.nearestKey(time).index;
    tag = marker.key(m).comment;
    if (tag == "In") { t = marker.key(m).time - time }
    else if (tag == "Out") { t = time - marker.key(m).time }
    linear(t, 0, framesToTime(fadeFrames), value, 0)
} else {
    value
}