let gridres = 20;

let tilesize = 25;

let origin = [0, 0];

let wid = 0;

​

function setup() {

  createCanvas(600, 1000, WEBGL);

  origin[0] = (tilesize * gridres) / 2;

  origin[1] = (tilesize * gridres) / 2;

  wid = gridres * tilesize;

}

​

function draw() {

  background(220);

  a[1] = 0.001 * sin(frameCount * 2);

  angleMode(DEGREES);

  rotateX(-90);

  translate(-origin[0], -origin[1] + 100, -200);

  for (let i = 0; i < gridres; i++) {

    for (let j = 0; j < gridres; j++) {

      let x = tilesize * j;

      let y = tilesize * i;

      if (

        pow(i - gridres / 2 + 0.5, 2) + pow(j - gridres / 2 + 0.5, 2) >=

        pow(gridres / 2, 2)

      ) {

        continue;

      }

      push();

      //noStroke();

      noFill();

      translate(x, y, 0);

      beginShape();

      vertex(0, 0, p(x, y));

      vertex(tilesize, 0, p(x + tilesize, y));

      vertex(tilesize, tilesize, p(x + tilesize, y + tilesize));

      vertex(0, tilesize, p(x, y + tilesize));

      endShape(CLOSE);

      pop();

    }

  }

  push();

  translate(0,wid/2,-300);

  box(10,10,10);

  rotateX(-90);

  rotateZ(20);

  translate(0,-450,0);

  cone(200,900);

  pop();

  push();

  //noStroke();

  fill(200)

  translate(0, 0, 400);

  beginShape();

  vertex(0, 0, 0);

  vertex(wid, 0, 0);

  vertex(wid, wid, 0);

  vertex(0, wid, 0);

  endShape(CLOSE);

  pop();

}

​

function p(x, y) {

  //return a[0] + a[1]*x + a[2]*y + a[3]*x*x + a[4]*x*y + a[5]*y*y;

  x -= origin[0];

  y -= origin[1];

  return a[1] * x * x;

}

​