3D Game Programming for Kids, 2nd Edition

Using Functions

Now that we understand what r() does, let’s put it to use. Back in the makePlanet() function, change the values of x, y, and z as shown.

​function​ makePlanet() {
  ​var​ size = 50;
  ​var​ x = r(1000) - 500;
  ​var​ y = r(1000) - 500;
  ​var​ z = r(1000) - 1000;
  ​var​ surface = ​'purple'​;

  ​var​ shape = ​new​ THREE.SphereGeometry(size);
  ​var​ cover = ​new​ THREE.MeshBasicMaterial({color: surface});
  ​var​ planet = ​new​ THREE.Mesh(shape, cover);
  planet.position.​set​(x, y, z);
  scene.add(planet);
}

Calling r(1000) will give us a random number between 0 and 1000. For x, we subtract 500 from r(1000) to give us a random number ...