CODEWITHSUNDEEP
javascripthtmlthree.js
madam_madman
madam_madman

Reputation: 79

New to three.js, how to animate this ball in three.js

Hi I'm just learning webGL and javascript.

I've made this three.js webGL scene thing, and actually come to think of it... They're the same object

http://goo.gl/gOiHX4

The ball is 'joined' to the rest of the 3d object, so I'll make a another sphere in blender by itself.

So say I have a ball.js and the rest of the structure, tribunal.js

how would I mode the ball.js along the 3D environment in this case?

Like maybe in a circle around the structure. constant loop.

pastebin for code too:

http://paste.ubuntu.com/6549663/

    <!doctype html>
<html lang="en">
<head>
  <title>My 3D webGL experiment</title>
  <meta charset="utf-8">
</head>
<body style="margin: 0;">

  <script src="js/three.min.js"></script>
  <script src="js/OrbitControls.js"></script>

  <script>

    // Set up the scene, camera, and renderer as global variables.
    var scene, camera, renderer;

    init();
    animate();

    // Sets up the scene.
    function init() {

      // Create the scene and set the scene size.
      scene = new THREE.Scene();
      var WIDTH = window.innerWidth,
          HEIGHT = window.innerHeight;

      // Create a renderer and add it to the DOM.
      renderer = new THREE.WebGLRenderer({antialias:true});
      renderer.setSize(WIDTH, HEIGHT);
      document.body.appendChild(renderer.domElement);

      // Create a camera, zoom it out from the model a bit, and add it to the scene.
      camera = new THREE.PerspectiveCamera(45, WIDTH / HEIGHT, 0.1, 20000);
      camera.position.set(90,80,0);
      scene.add(camera);

      // Create an event listener that resizes the renderer with the browser window.
      window.addEventListener('resize', function() {
        var WIDTH = window.innerWidth,
            HEIGHT = window.innerHeight;
        renderer.setSize(WIDTH, HEIGHT);
        camera.aspect = WIDTH / HEIGHT;
        camera.updateProjectionMatrix();
      });

      // Set the background color of the scene.
      renderer.setClearColorHex(0xB5DBDB, 1);

      // Create a light, set its position, and add it to the scene.
      var light = new THREE.PointLight(0xf44fff);
      light.position.set(200,200,200);
      scene.add(light);

      // Load in the mesh and add it to the scene.
      var loader = new THREE.JSONLoader();
      loader.load( "models/tribunal.js", function(geometry){
        var material = new THREE.MeshLambertMaterial({color: 0xCC0000});
        mesh = new THREE.Mesh(geometry, material);
        scene.add(mesh);
      });

      // Add OrbitControls so that we can pan around with the mouse.
      controls = new THREE.OrbitControls(camera, renderer.domElement);

    }


    // Renders the scene and updates the render as needed.
    function animate() {

      // Read more about requestAnimationFrame at http://www.paulirish.com/2011/requestanimationframe-for-smart-animating/
      requestAnimationFrame(animate);

      // Render the scene.
      renderer.render(scene, camera);
      controls.update();

    }

  </script>

</body>
</html>

Upvotes: 1

Views: 1760

Answers (1)

Zob
Zob

Reputation: 470

In THREE.js, any movement of an object can be accomplished by changing its properties: position, rotation and/or scale. These properties are not simple numbers, so changing them to suit your needs often requires using built-in functions to be sure the change is handled correctly. For example, the position of a mesh is defined as a Vector which can be changed using the set() function like so:

mesh.position.set( 0, 0, 0 ); // Standard [ x, y, z ] coordinate system

There are many other ways to change the values in a Vector described in the documentation and code. Think of the properties of an object as objects themselves, and familiarize yourself with the methods available to you for those objects and their parent objects.

To answer your question: continuously moving an object over a period of time requires more code inside your animate() function. The following code will move a mesh 1 unit in a positive direction along the x-axis every time the animate() function is called:

mesh.position.translateX( 1 );

Tips:

  • There are many types of movement, but they are mostly combinations of position, rotation, and/or scale.

  • It is important to remember that child objects are affected by parent objects. If Mesh B is attached to Mesh A, movement applied to Mesh A will move Mesh B as well.

  • Variable references to objects inside your animate() loop need to be global so the animate() loop knows what object you are talking about.

  • Changes in position, scale and even rotation can quickly move an object out of frustum (or field-of-view) of the camera.

  • Use OrbitControls.js and console.log() to help debug animations.

Upvotes: 2

Related Questions