examples/example08.html

<!DOCTYPE html>
<html>
 <head> 
  <title>Example 8 - Camera helper</title> 
  <style>
    body{
      margin: 0;
      overflow: hidden;
    }

    #stats {  /* Align stats top-left */
      position: absolute;
      left: 0px;
      top: 0px;
    }
  </style> 
  </head>
  <body>
  <!-- JavaScript libraries -->
  <script src="http://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 
  <script src="http://cdnjs.cloudflare.com/ajax/libs/three.js/r67/three.min.js"></script>
  <script src="http://cdnjs.cloudflare.com/ajax/libs/stats.js/r11/Stats.min.js"></script>
  <script src="http://cdnjs.cloudflare.com/ajax/libs/dat-gui/0.5/dat.gui.min.js"></script>
  <script src="assets/libs/TrackballControls.js"></script>
  <!-- Javascript code that runs our Three.js examples --> 
  <script>
    // once everything is loaded, we run our Three.js stuff.
    $(function () {

      var stats = initStats();

      // create a scene, that will hold all our elements such as objects, cameras and lights.
      var scene = new THREE.Scene();

      // create a camera, which defines where we're looking at.
      var camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);

      // create a inspectedCamera
      var inspectedCamera = new THREE.PerspectiveCamera(10, window.innerWidth / window.innerHeight, 10, 70);

      // create a render and set the size
      var renderer = new THREE.WebGLRenderer();

      // create trackball controls
      var trackballControls = new THREE.TrackballControls(camera);

      renderer.setClearColor(new THREE.Color(0xEEEEEE, 1.0));
      renderer.setSize(window.innerWidth, window.innerHeight);

      // create the ground plane
      var planeGeometry = new THREE.PlaneGeometry(60,20);
      var planeMaterial =  new THREE.MeshLambertMaterial({color: 0xffffff});
      var plane = new THREE.Mesh(planeGeometry,planeMaterial);

      // rotate and position the plane
      plane.rotation.x=-0.5*Math.PI;
      plane.position.set(15,0,0);

      // add the plane to the scene
      scene.add(plane);

      // create a cube
      var cubeGeometry = new THREE.BoxGeometry(4,4,4);
      var cubeMaterial = new THREE.MeshLambertMaterial({color: 0xff0000});
      var cube = new THREE.Mesh(cubeGeometry, cubeMaterial);

      // position the cube
      cube.position.set(-4,3,0);

      // add the cube to the scene
      scene.add(cube);

      var sphereGeometry = new THREE.SphereGeometry(4,20,20);
      var sphereMaterial = new THREE.MeshLambertMaterial({color: 0x7777ff});
      var sphere = new THREE.Mesh(sphereGeometry,sphereMaterial);

      // position the sphere
      sphere.position.set(20,4,2);

      // add the sphere to the scene
      scene.add(sphere);

      // position and point the camera to the center of the scene
      camera.position.set(-30,40,30);
      camera.up = new THREE.Vector3(0,1,0);
      camera.lookAt(scene.position);

      // position and point the camera to the center of the scene
      inspectedCamera.position.set(30,40,-30);
      inspectedCamera.up = new THREE.Vector3(0,1,0);
      inspectedCamera.lookAt(scene.position);

      // add subtle ambient lighting
      var ambientLight = new THREE.AmbientLight(0x0c0c0c);
      scene.add(ambientLight);

      // add spotlight for the shadows
      var spotLight = new THREE.SpotLight( 0xffffff );
      spotLight.position.set(-40,60,-10);
      scene.add(spotLight);

      // add cameraHelper
      var cameraHelper = new THREE.CameraHelper(inspectedCamera);
      scene.add(inspectedCamera);
      scene.add(cameraHelper);

      // add the output of the renderer to the html element
      $('body').append(renderer.domElement);

      // call the render function
      var step = 0;

      var controls = new function () {
        this.rotationSpeed = 0.02;
        this.bouncingSpeed = 0.03;
        this.inspectedCamera = false;
      };

      var gui = new dat.GUI();
      var rotationControl = gui.add(controls, 'rotationSpeed',0,0.2);
      var bouncingControl = gui.add(controls, 'bouncingSpeed',0,0.2);
      var cameraControl = gui.add(controls, 'inspectedCamera');

      render();

      var renderCamera = camera;

      cameraControl.onChange(function (value) {
        renderCamera = value ? inspectedCamera : camera;
      });

      function render() {
        stats.update();
        trackballControls.update();
        cameraHelper.update();

        // rotate the cube around its axis
        cube.rotation.x += controls.rotationSpeed;
        cube.rotation.y += controls.rotationSpeed;
        cube.rotation.z += controls.rotationSpeed;

        // bounce the sphere up and down
        step += controls.bouncingSpeed;
        sphere.position.x = 20+( 10*(Math.cos(step)));
        sphere.position.y = 2 +( 10*Math.abs(Math.sin(step)));

        // render using requestAnimationFrame
        requestAnimationFrame(render);
        renderer.render(scene, renderCamera);
      }

      function initStats() {
        var stats = new Stats();
        stats.setMode(0); // 0: fps, 1: ms
        $('body').append(stats.domElement);
        return stats;
      }
    });
  </script>  
 </body>
</html>