More cleanup?

assets/scenes/cube.js

@@ -5,15 +5,14 @@ function CubeScene() {
   this.cam.add(POSITION);
   this.cam.add(CAMERA);
 
-  this.cam.position.x = 3;
-  this.cam.position.y = 3;
-  this.cam.position.z = 3;
-  this.cam.position.lookAt(0, 0, 0);
+  this.cam.position.position = new Vec3(3, 3, 3);
+  this.cam.position.lookAt(new Vec3(0, 0, 0));
 
   this.cube = new Cube();
 }
 
-Object.assign(CubeScene, Scene.prototype);
+CubeScene.prototype = Object.create(Scene.prototype);
+CubeScene.prototype.constructor = CubeScene;
 
 CubeScene.prototype.update = function() {
   this.cube.update();