I'm new to after effects, I wanted to create a simple flicker effect, and I thought the way to do this would be to add a noise function to the brightness/opacity property. I feel like my thinking is way off mark though because I searched around and no one even mentions the existance of such a function, or even mentions the need for such behaviour. I found a "wiggle" function that seems to be made specifically for position translation. Is there anyway to get a noise function that outputs values from, say, a 1D perlin noise map, and then somehow plug the output to any keyable property of an element? Even just a random number gen. If doing this ends up needing scripting/expressions, could you point me to resources that could get me started with custom AE expressions? Thanks in advance.
wiggle() is your Perlin noise and just because a majority of people use it on position doesn't mean it can't be applied to other properties. Rather than relying on questionable tutorials on the Internet a simple excursion to the online help section on expressions could have told you that and on top of it educated you about other random functions as well.
The expression system is very streamlined. Literally put "wiggle()", nothing like "setBrightness(noise(iterator))" or anything like that(tbf wiggle is a pretty funny name for this function). Will look further into expressions to see if there is a more hands on expression system with a bit more user control.
On top of this, found an opacity flash effect. It already exists! Yay!