Cannot get objects to appear in scene in JavaScript

V Nadeau
V Nadeau used Ask the Experts™
on
H. I am following a book that is supposed to show me how to create a solar system in JavaScript. The problem is that none of my objects appear on the screen, no sun, earth or mars. Can anyone please tell me what is wrong with this code or what I am missing?

Code:
******************************************************************

<body></body>
<script src="http://gamingJS.com/Three.js"></script>
<script src="http://gamingJS.com/ChromeFixes.js"></script>
<script>

  // This is where stuff in our game will happen:
  var scene = new THREE.Scene();

  // This is what sees the stuff:
  var aspect_ratio = window.innerWidth / window.innerHeight;
  var camera = new THREE.PerspectiveCamera(75, aspect_ratio, 1, 1e6);
  camera.position.z = -1000;
  scene.add(camera);

  // This will draw what the camera sees onto the screen:
  var renderer = new THREE.WebGLRenderer();
  renderer.setSize(window.innerWidth, window.innerHeight);
  document.body.appendChild(renderer.domElement);

  // ******** START CODING ON THE NEXT LINE ********
document.body.style.backgroundColor = 'black';
var star = new THREE.SphereGeometry(500,28,21);
var surface = new THREE.MeshPhongMaterial({ambient: 0xFFD700, color: 0x0000cd});
var sun = new THREE.Mesh(star,surface);
scene.add(sun);

var ambient = new THREE.AmbientLight(0xffffff);
var sunlight = new THREE.PointLight(0xffffff,5,1000);
sun.add(sunlight);

var surface = new THREE.MeshPhongMaterial({ambient: 0x1a1a1a, color: 0x0000cd});
var planet = new THREE.SphereGeometry(20,20,15);
var earth = new THREE.Mesh(earth,surface);
earth.position.set(250,0,0);
scene.add(earth);

var surface = new THREE.MeshPhongMaterial({ambient: 0x1a1a1a, color: 0xb22222});
var planet = new THREE.SphereGeometry(20,20,15);
var mars = new THREE.Mesh(mars,surface);
mars.position.set(500,0,0);
scene.add(mars);

var stars = new THREE.Geometry();
while (stars.vertices.length < 1e4) {
  var lat = Math.PI * Math.random() - Math.PI/2
  var lon = 2*Math.PI * Math.random();
 
  stars.vertices.puch(new THREE.Vector3(
    1e5 * Math.cos(lon) * Math.cos(lat),
    1e5 * Math.sin(lon) * Math.cos(lat),
    1e5 * Math.sin(lat)
    ));
}

clock = new THREE.Clock();

function animate() {
  requestAnimationFrame(animate);
 
  var time = clock.getElapsedTime;
 
  var e_angle = time * 0.8;
  earth.position.set(250* Math.cos(e_angle), 250* Math.sin(e_angle), 0);
 
  // Now, show what the camera sees on the screen:
  renderer.render(scene, camera);
}

animate;
 
</script>
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have you tried replacing the last line
animate;

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with
animate();

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Author

Commented:
Thanks for catching that. It was an error but fixing it still does not make the objects appear.
Distinguished Expert 2017
Commented:
You have a syntax error at this:
stars.vertices.puch(new THREE.Vector3(

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The correct is this:
stars.vertices.push(new THREE.Vector3(

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Commented:
Thank you for your feedback. There was actually alot missing from my code which I fixed. Now the sun, earth and mars will display, and earth and mars rotates around the sun. The problem remaining  is that the stars do not appear and the keydown events do nothing. I think I will start a new question for this with the revised code, otherwise it just looks confusing. Here is what I have so far:

code:
*************************************************************************

<body></body>
<script src="http://gamingJS.com/Three.js"></script>
<script src="http://gamingJS.com/ChromeFixes.js"></script>
<script>

  // This is where stuff in our game will happen:
  var scene = new THREE.Scene();

  // This is what sees the stuff:
  var aspect_ratio = window.innerWidth / window.innerHeight;
  var above_cam = new THREE.PerspectiveCamera(75, aspect_ratio, 1, 1e6);
  above_cam.position.z = 1000;
  scene.add(above_cam);

  var earth_cam = new THREE.PerspectiveCamera(75, aspect_ratio, 1, 1e6);
  scene.add(earth_cam);
 
  var camera = above_cam;
 
  // This will draw what the camera sees onto the screen:
  var renderer = new THREE.WebGLRenderer();
  renderer.setSize(window.innerWidth, window.innerHeight);
  document.body.appendChild(renderer.domElement);

  // ******** START CODING ON THE NEXT LINE ********
document.body.style.backgroundColor = 'black';

var star = new THREE.SphereGeometry(50,28,21);
var surface = new THREE.MeshPhongMaterial({ambient: 0xFFD700, color: 0x0000cd});
var sun = new THREE.Mesh(star, surface);
scene.add(sun);

var planet = new THREE.SphereGeometry(20,20,15);
var surface = new THREE.MeshPhongMaterial({ambient: 0x1a1a1a, color: 0xFFD700});
var earth = new THREE.Mesh(planet, surface);
earth.position.set(250,0,0);
scene.add(earth);

var planet2 = new THREE.SphereGeometry(20,20,15);
var surface = new THREE.MeshPhongMaterial({ambient: 0x1a1a1a, color: 0xb22222});
var mars = new THREE.Mesh(planet2, surface);
mars.position.set(500,0,0);
scene.add(mars);

var ambient = new THREE.AmbientLight(0xffffff);
scene.add(ambient);
var sunlight = new THREE.PointLight(0xffffff,5,1000);
sun.add(sunlight);

var stars = new THREE.Geometry();
while (stars.vertices.length < 1e4) {
  var lat = Math.PI * Math.random() - Math.PI/2;
  var lon = 2*Math.PI * Math.random();
 
  stars.vertices.push(new THREE.Vector3(
    1e5 * Math.cos(lon) * Math.cos(lat),
    1e5 * Math.sin(lon) * Math.cos(lat),
    1e5 * Math.sin(lat)
    ));
}

var star_stuff = new THREE.ParticleBasicMaterial({size: 500});
var star_system = new THREE.ParticleBasicMaterial(stars, star_stuff);
scene.add(star_system);


clock = new THREE.Clock();

function animate() {
  requestAnimationFrame(animate);
 
  var time = clock.getElapsedTime();
 
  var e_angle = time * 0.8;
  earth.position.set(250* Math.cos(e_angle), 250* Math.sin(e_angle), 0);
 
  var m_angle = time * 0.3;
  mars.position.set(500* Math.cos(m_angle), 500* Math.sin(m_angle), 0);
 
  var y_diff = mars.position.y - earth.position.y,
    x_diff = mars.position.x - earth.position.x,
    angle = Math.atan2(x_diff, y_diff);
   
  earth_cam.rotation.set(Math.PI/2, -angle, 0);
  earth_cam.position.set(earth.position.x, earth.position.y, 22);
 
    // Now, show what the camera sees on the screen:
  renderer.render(scene, camera);
}

animate();


document.addEventListener("keydown", function(event) {
  var code = event.keycode;
 
  if (code == 65) {     //A
    camera = above_cam;
  }
   if (code == 69) {     //E
    camera = earth_cam;
  }
});

</script>

</script>

Author

Commented:
I realized that there was information in the book that I had not typed in. Adding this extra code solved a big part of my problem.

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