let increment = 0.01
let octaves = 3
let falloff = 0.3

function setup() {
    createCanvas(640, 240)
    pixelDensity(1)
    noiseDetail(octaves, falloff)
}

function draw() {
    loadPixels()
    for (let x = 0; x < width; x++) {
        for (let y = 0; y < height; y++) {
            let index = (x + y * width) * 4

            let noiseValue = noise(x*increment, y*increment)
            let bright = map(noiseValue, 0, 1, 0, 255)
            pixels[index+0] = bright
            pixels[index+1] = bright
            pixels[index+2] = bright
            pixels[index+3] = 255
        }
    }
    updatePixels()
}