A number of steps are necessary to enable lighting for visual objects in the virtual universe. In addition to creating and customizing light objects, each light object must be added to the scene graph and have a bounds object specified. Each visual object to be shaded must have surface normals and material properties.

In this program, Sphere class of geometry utility classes defines the normals and material by itself. So we should focus on how to add the lights into the world.

 class LightTheWorld extends JFrame {

    // Define the light objects
    private AmbientLight ambientLight=new AmbientLight();
    private DirectionalLight lightA=new DirectionalLight();
    private DirectionalLight lightB=new DirectionalLight();
    
    private Sphere sphere=new Sphere(0.4f);
    ...
  

    BranchGroup createScene() {
       ...
    
       BoundingSphere bound=new BoundingSphere();
    
       //Config the light
       ambientLight.setInfluencingBounds(bound);
       ambientLightBG.addChild(ambientLight);
       ambientLightBG.setCapability(BranchGroup.ALLOW_DETACH);
    
       Vector3f directionA = new Vector3f(-1.0f, -1.0f, -0.5f);
       directionA.normalize();
       lightA.setDirection(directionA);
       lightA.setColor(new Color3f(0.0f, 0.0f, 1.0f));
       lightA.setInfluencingBounds(bound);
       lightABG.addChild(lightA);
    
       Vector3f directionB = new Vector3f(1.0f, -1.0f, -0.5f);
       directionB.normalize();
       lightB.setDirection(directionB);
       lightB.setColor(new Color3f(1.0f, 0.0f, 0.0f));
       lightB.setInfluencingBounds(bound);
       lightBBG.addChild(lightB);
       
       ...
    }
    
    ...
}