createCanvas(400, 400,SVG);

  angleMode(DEGREES);

}

​

let noiseScale = 0.1;

​

function draw() {

  background(220);

  let begin = width / 4;

  let end = width - begin;

  let space = 15;

  noFill();

  hourGlass(begin, height/8, end, space);

  save("waveline.svg");

  noLoop();

}

​

function hourGlass(x, y, len, spacing) {

  let heightMap = map(y, 0, 10, 0, 1);

  noFill();

  beginShape(POINTS);

  for (let v = y; v < len; v += spacing) {

    for (let h = x; h < len; h+=0.2) {

      let j = y + map(sin(noiseScale + heightMap * h), 0, 1, 0, 10);

      vertex(h, v + j);

      vertex(h, -v + j + 300);

    }

    x += spacing;

    len -= spacing;

  }

  endShape();

}

​