const r_offset = 100;

const r_depth = 50;

let theta = 0;

let theta_a = 0.1;

​

let phi = 0;

let phi_a = 0.6;

​

function setup() {

  createCanvas(400, 400);

  background(220);

}

​

function draw() {

  translate(width/2, height/2);

  const x = r*cos(theta);

  const y = r*sin(theta);

  ellipse(x, y, 10, 10);

  r = r_offset + r_depth*sin(phi);

  theta += theta_a;

  phi += phi_a;

}