Focus on the Moon v3

by Lukasz Guminski

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/98/three.min.js"></script>
<script src="https://threejs.org/examples/js/controls/OrbitControls.js"></script>
<script src="https://threejs.org/examples/js/renderers/CSS2DRenderer.js"></script>

CSS

body {
	  margin: 0;
}

#info {
  position: absolute;
  left: 1em;
  top: 1em;
  background: rgba(0, 0, 0, .8);
  padding: .5em;
  color: white;
  font-family: monospace;
}

JavaScript

var camera, controls, scene, renderer, labelRenderer;
var solarPlane, earth, moon;
var angle = 0;
const p = new THREE.Vector3();
const q = new THREE.Quaternion();
const s = new THREE.Vector3();

function buildScene() {
  scene = new THREE.Scene();
  solarPlane = createSolarPlane();
  earth = createBody("Earth");
  moon = createBody("Moon");

  scene.add(solarPlane);
  solarPlane.add(earth);
  earth.add(moon);

  moon.add(camera);
}

init();
animate();

function init() {

  renderer = new THREE.WebGLRenderer({
    antialias: false
  });
  renderer.setPixelRatio(window.devicePixelRatio);
  renderer.setSize(window.innerWidth, window.innerHeight);
  document.body.appendChild(renderer.domElement);

  labelRenderer = new THREE.CSS2DRenderer();
  labelRenderer.setSize(window.innerWidth, window.innerHeight);
  labelRenderer.domElement.style.position = 'absolute';
  labelRenderer.domElement.style.top = '0';
  labelRenderer.domElement.style.pointerEvents = 'none';
  document.body.appendChild(labelRenderer.domElement);

  camera = new THREE.PerspectiveCamera(60, window.innerWidth / window.innerHeight, 0.1, 1000);
  camera.position.set(13.670839104116506, 10.62941701834559, 0.3516419193657562);
  camera.lookAt(0, 0, 0);

  buildScene();
  
  controls = new THREE.OrbitControls(camera, renderer.domElement);
  controls.enablePan = false;
  controls.enableDamping = false;
}

function animate(time) {

  angle = (angle + .005) % (2 * Math.PI);
  rotateBody(earth, angle, 1);
  rotateBody(moon, angle, 2);

  moon.matrixWorld.decompose(p, q, s);
  controls.target.copy(p);

  render();
  requestAnimationFrame(animate);

  function rotateBody(body, angle, radius) {
    body.rotation.x = angle;
    body.position.x = radius * Math.cos(angle);
    body.position.y = radius * Math.sin(angle);
    body.position.z = radius * Math.sin(angle);
  }
}

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

function createBody(name, parent) {
  var geometry...