[Jason Gold]

One layer.

I can think of a few examples once I know the correct syntax, but for now let me stick with particles. An emitter is spraying out a narrow stream of particles from one side of the screen to the other. If I apply wiggle(5,50) to the position property, every particle will wiggle randomly. I would prefer that each particle gradually become turbulent due to the wiggle.

I’ve tried using a slider with keyframes at the beginning and end of the comp, but this gradually increases the wiggle of every particle on the screen. If I could somehow link the age of young particles to be 0% affected by the wiggle, and old particles to be 100% affected by the wiggle it would appear that the turbulence gradually increases.

I also thought of trying to use the color-at-birth and color-at-death parameters to control the percentage of wiggle so that it gradually increases. White particles = 0% wiggle; and Black particles = 100% wiggle. In this case I can imagine that a Luminosity value of a particle could control a percentage of wiggle(5,50) — such as: a gray particle (being 50% luma) might result in wiggle(5,25). In plain language, [If hex code of particle = #ffffff, then wiggle(5,0)] and [If hex code of particle = #000000, then wiggle(5,50)].

Another way to describe what want is by looking at the Opacity Map for particles. We can draw ramp/curve to fade the particles in/out. If “Wiggle” had this map I could tell AE that new particles don’t wiggle and old particles wiggle a lot…..but,, maybe in a later update. 🙂