Processing Evolved

    function setup() {
        let canvas = createCanvas(600, 600, WEBGL);
        canvas.parent('animation-holder');
    resizeAnimation();
    }

    let pieces = [];
    let hue = 0;

    function draw() {
        background(150);
        translate(0, 0, 60);
        rotateX(frameCount * 0.01);
        rotateY(frameCount * 0.02);

        for (let i = 0; i < pieces.length; i++) {
            let piece = pieces[i];
            piece.update();
            piece.display();
        }

        if (pieces.length < 100) {
            let newPiece = new Piece(0, 0, 100);
            pieces.push(newPiece);
        }
    }

    class Piece {
        constructor(x, y, size) {
            this.x = x;
            this.y = y;
            this.size = size;
            this.vx = random(-2, 2);
            this.vy = random(-2, 2);
            this.hue = hue;
            hue = (hue + 20) % 360;
        }

        update() {
            this.x += this.vx;
            this.y += this.vy;
            this.size *= 0.99;
        }

        display() {
            push();
            translate(this.x, this.y);
            fill(this.hue, 255, 255);
            box(this.size);
            pop();
        }
    }