I'm working on a project where I need to have, due to the size of the composition, thousands of small squares vary in opacity over time. I have been attempting to use expressions to map the value of a fractal noise control layer to the opacity value of the squares using point sampling, which after struggling with for a while i got to vaguely work. The computer I have to use is not very powerful at all so I have yet to see the opacity change dynamically. I know that I can make lots of copies of a square using repeat, but I'm afraid that the squares will only vary according to the value behind the original square, making all the squares change at the same rate, not vary individually, making rolling patches of opaque squares.
Below is the expression I'm using to control the opacity
"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.