title: I'm doing something wrong with SpotLights and shadows in Three.js
body: <p>I have a really simple scene which has one .dae mesh in it, and a 7000*7000 plane underneath the mesh. I'd like it to be lit by a high <code>SpotLight</code>, so the mesh throws a shadow on the ground. But, something seems to be broken! No matter how high I put the <code>SpotLight</code>, it never lights up the plane! Also, it lights the mesh up only a little, while it is in a small square (perimeter).</p>
  
  <p>You can see the situation here:
  <img src="https://i.stack.imgur.com/UFstg.jpg" alt="Screenshot1, almost everything is dark"></p>
  
  <p>As soon as I move the mesh (a monster) around, it wont be lit anymore.</p>
  
  <p>This is how I instantiate the light:</p>
  
  <pre><code>// create a spotlight
  self.spotLight = new THREE.SpotLight();
  
  // set its position
  self.spotLight.position.y = 1000; //I recon it needs to be relatively high so it lights up everything
  self.spotLight.position.x = 0; //(0, 0) are the coordinates where the mesh is spawned, and are the center of the plane
  self.spotLight.position.z = 0;
  self.spotLight.castShadow = true;
  </code></pre>
  
  <p>This is how the plane is made:</p>
  
  <pre><code>//The plane.
  self.plane = new THREE.Mesh(new THREE.PlaneGeometry(self.groundSize, self.groundSize), new THREE.MeshLambertMaterial({color: 0x5C8A00}));
  self.plane.receiveShadow = true;
  self.plane.position.x = 0;
  self.plane.position.y = -26;
  self.plane.position.z = 0;
  </code></pre>
  
  <p>Also, here's another picture, this time, I've added a lot of <code>PointLights</code>:</p>
  
  <p><img src="https://i.stack.imgur.com/QQoru.jpg" alt="Screenshot2, everything is lit up."></p>
  
  <p>You can see how the shadow still disappears!</p>
  
  <p>Now, what am I doing wrong here? AFAIK, light should disperse equally in all directions! And also, there is another problem, I seem to be unable to add multiple SpotLights on the scene! Everything slows down completely if I do so - is this intended? Maybe it's because I enabled shadows on all of them...</p>
  
  <p>@Neil, the same thing happens in your code as well!</p>
  
  <p><img src="https://i.stack.imgur.com/o1eiT.jpg" alt="enter image description here"></p>