examples/example11.html



<!DOCTYPE html>
<html>
 <head> 
  <title>Example 11 - Spot light</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 stopMovingLight = false;

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

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

      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, 1, 1);
      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: 0xff3333});
      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(20,0,2);

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

      // position and point the camera to the center of the scene
      camera.position.set(-35,30,25);
      camera.lookAt(new THREE.Vector3(10, 0, 0));

      // add subtle ambient lighting
      var ambiColor = "#1c1c1c";
      var ambientLight = new THREE.AmbientLight(ambiColor);
      scene.add(ambientLight);

      // add spotlight for a bit of light
      var spotLight0 = new THREE.SpotLight(0xcccccc);
      spotLight0.position.set(-40, 60, -10);
      spotLight0.lookAt(plane);
      scene.add(spotLight0);

      var target = new THREE.Object3D();
      target.position = new THREE.Vector3(5, 0, 0);

      var pointColor = "#ffffff";
      var spotLight = new THREE.SpotLight(pointColor);
      spotLight.position.set(-40, 60, -10);
      spotLight.target = plane;
      spotLight.distance = 25;
      spotLight.angle = 0.75;
      spotLight.exponent = 30;

      scene.add(spotLight);

      // add spotlight helper
      var spotLightHelper = new THREE.SpotLightHelper(spotLight);
      scene.add(spotLightHelper);

      // add a small sphere simulating the pointlight
      var sphereLight = new THREE.SphereGeometry(0.2);
      var sphereLightMaterial = new THREE.MeshBasicMaterial({color: 0xac6c25});
      var sphereLightMesh = new THREE.Mesh(sphereLight, sphereLightMaterial);

      sphereLightMesh.position = new THREE.Vector3(3, 20, 3);
      scene.add(sphereLightMesh);


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

      // call the render function
      var step = 0;

      // used to determine the switch point for the light animation
      var invert = 1;
      var phase = 0;

      var controls = new function () {
        this.rotationSpeed = 0.03;
        this.bouncingSpeed = 0.03;
        this.ambientColor = ambiColor;
        this.pointColor = pointColor;
        this.intensity = 1;
        this.distance = 90;
        this.exponent = 30;
        this.angle = 0.75;
        this.debug = false;
        this.onlyShadow = false;
        this.target = "Plane";
        this.stopMovingLight = false;
      }

      var gui = new dat.GUI();
      gui.addColor(controls, 'ambientColor').onChange(function (e) {
        ambientLight.color = new THREE.Color(e);
      });

      gui.addColor(controls, 'pointColor').onChange(function (e) {
        spotLight.color = new THREE.Color(e);
      });

      gui.add(controls, 'angle', 0, Math.PI / 2).onChange(function (e) {
        spotLight.angle = e;
      });

      gui.add(controls, 'intensity', 0, 5).onChange(function (e) {
        spotLight.intensity = e;
      });

      gui.add(controls, 'distance', 0, 200).onChange(function (e) {
        spotLight.distance = e;
      });

      gui.add(controls, 'exponent', 0, 100).onChange(function (e) {
        spotLight.exponent = e;
      });

      gui.add(controls, 'target', ['Plane', 'Sphere', 'Box']).onChange(function (e) {
        console.log(e);
        switch (e) {
          case "Plane":
            spotLight.target = plane;
            break;
          case "Sphere":
            spotLight.target = sphere;
            break;
          case "Box":
            spotLight.target = cube;
            break;
        }
      });

      gui.add(controls, 'stopMovingLight').onChange(function (e) {
          stopMovingLight = e;
      });

      render();

      function render() {
        stats.update();
        // trackballControls.update();
        spotLightHelper.update();

        // rotate the cube around its axes
        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)));

        // move the light simulation
        if (!stopMovingLight) {
          if (phase > 2 * Math.PI) {
            invert = invert * -1;
            phase -= 2 * Math.PI;
          } else {
            phase += controls.rotationSpeed;
          }
          sphereLightMesh.position.z = +(7 * (Math.sin(phase)));
          sphereLightMesh.position.x = +(14 * (Math.cos(phase)));

          if (invert < 0) {
            var pivot = 14;
            sphereLightMesh.position.x = (invert * (sphereLightMesh.position.x - pivot)) + pivot;
          }

          spotLight.position = sphereLightMesh.position;
        }

        // render using requestAnimationFrame
        requestAnimationFrame(render);

        renderer.render(scene, camera);
      }

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