utilities.js

function render() {
  renderer.render( scene, camera );
}

function animate() {
  // render the 3D scene
  render();
  requestAnimationFrame( animate );
}

// Call the three scene initialisation, attach the resize event and start the animation requestAnimationFrame.
function init () {
  initThree()
  resize()
  window.addEventListener('resize', resize, { passive: true
  })
  addInstancedMesh()
  animate()
}
init()