This Java tip builds a red sphere using the Sphere utility class and adds lights so that you can see it shape. It creates a material for the sphere, creates an ambient light and a one directional light.

 import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.media.j3d.AmbientLight;
import javax.media.j3d.Appearance;
import javax.media.j3d.BoundingSphere;
import javax.media.j3d.BranchGroup;
import javax.media.j3d.Canvas3D;
import javax.media.j3d.DirectionalLight;
import javax.media.j3d.Locale;
import javax.media.j3d.Material;
import javax.media.j3d.PhysicalBody;
import javax.media.j3d.PhysicalEnvironment;
import javax.media.j3d.Transform3D;
import javax.media.j3d.TransformGroup;
import javax.media.j3d.View;
import javax.media.j3d.ViewPlatform;
import javax.media.j3d.VirtualUniverse;
import javax.vecmath.AxisAngle4d;
import javax.vecmath.Color3f;
import javax.vecmath.Point3d;
import javax.vecmath.Vector3f;

import com.sun.j3d.utils.geometry.Sphere;

/**
 * This builds a red sphere using the Sphere utility class and adds lights so
 * that you can see it shape. It creates a material for the sphere, creates an
 * ambient light and a one directional light.
 * 
 * @author I.J.Palmer
 * @version 1.0
 */
public class SimpleDirLight extends Frame implements ActionListener {
  protected Canvas3D myCanvas3D = new Canvas3D(null);

  protected Button myButton = new Button("Exit");

  /**
   * This function builds the view branch of the scene graph. It creates a
   * branch group and then creates the necessary view elements to give a
   * useful view of our content.
   * 
   * @param c
   *            Canvas3D that will display the view
   * @return BranchGroup that is the root of the view elements
   */
  protected BranchGroup buildViewBranch(Canvas3D c) {
    BranchGroup viewBranch = new BranchGroup();
    Transform3D viewXfm = new Transform3D();
    viewXfm.set(new Vector3f(0.0f, 0.0f, 10.0f));
    TransformGroup viewXfmGroup = new TransformGroup(viewXfm);
    ViewPlatform myViewPlatform = new ViewPlatform();
    PhysicalBody myBody = new PhysicalBody();
    PhysicalEnvironment myEnvironment = new PhysicalEnvironment();
    viewXfmGroup.addChild(myViewPlatform);
    viewBranch.addChild(viewXfmGroup);
    View myView = new View();
    myView.addCanvas3D(c);
    myView.attachViewPlatform(myViewPlatform);
    myView.setPhysicalBody(myBody);
    myView.setPhysicalEnvironment(myEnvironment);
    return viewBranch;
  }

  /**
   * This creates some lights and adds them to the BranchGroup.
   * 
   * @param b
   *            BranchGroup that the lights are added to.
   */
  protected void addLights(BranchGroup b) {
    // Create a bounds for the lights
    BoundingSphere bounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0),
        100.0);
    //Set up the ambient light
    Color3f ambientColour = new Color3f(0.2f, 0.2f, 0.2f);
    AmbientLight ambientLight = new AmbientLight(ambientColour);
    ambientLight.setInfluencingBounds(bounds);
    //Set up the directional light
    Color3f lightColour = new Color3f(1.0f, 1.0f, 1.0f);
    Vector3f lightDir = new Vector3f(-1.0f, -1.0f, -1.0f);
    DirectionalLight light = new DirectionalLight(lightColour, lightDir);
    light.setInfluencingBounds(bounds);
    //Add the lights to the BranchGroup
    b.addChild(ambientLight);
    b.addChild(light);
  }

  /**
   * This build the content branch of our scene graph. It creates a transform
   * group so that the shape is slightly tilted to reveal its 3D shape.
   * 
   * @param shape
   *            Node that represents the geometry for the content
   * @return BranchGroup that is the root of the content branch
   */
  protected BranchGroup buildContentBranch() {
    BranchGroup contentBranch = new BranchGroup();
    Transform3D rotateCube = new Transform3D();
    rotateCube.set(new AxisAngle4d(1.0, 1.0, 0.0, Math.PI / 4.0));
    TransformGroup rotationGroup = new TransformGroup(rotateCube);
    contentBranch.addChild(rotationGroup);
    //Create a new appearance
    Appearance app = new Appearance();
    //Create the colours for the material
    Color3f ambientColour = new Color3f(1.0f, 0.0f, 0.0f);
    Color3f diffuseColour = new Color3f(1.0f, 0.0f, 0.0f);
    Color3f specularColour = new Color3f(1.0f, 1.0f, 1.0f);
    Color3f emissiveColour = new Color3f(0.0f, 0.0f, 0.0f);
    //Define the shininess
    float shininess = 20.0f;
    //Set the material of the appearance
    app.setMaterial(new Material(ambientColour, emissiveColour,
        diffuseColour, specularColour, shininess));
    //Create and add a new sphere using the appearance
    rotationGroup.addChild(new Sphere(2.0f, Sphere.GENERATE_NORMALS, 120,
        app));
    //Use the addLights function to add the lights to the branch
    addLights(contentBranch);
    //Return the root of the content branch
    return contentBranch;
  }

  /**
   * Handles the exit button action to quit the program.
   */
  public void actionPerformed(ActionEvent e) {
    dispose();
    System.exit(0);
  }

  /**
   * This creates a default universe and locale, creates a window and uses the
   * functions defined in this class to build the view and content branches of
   * the scene graph.
   */
  public SimpleDirLight() {
    VirtualUniverse myUniverse = new VirtualUniverse();
    Locale myLocale = new Locale(myUniverse);
    myLocale.addBranchGraph(buildViewBranch(myCanvas3D));
    myLocale.addBranchGraph(buildContentBranch());
    setTitle("SimpleDirLight");
    setSize(400, 400);
    setLayout(new BorderLayout());
    add("Center", myCanvas3D);
    add("South", myButton);
    myButton.addActionListener(this);
    setVisible(true);
  }

  public static void main(String[] args) {
    SimpleDirLight sdl = new SimpleDirLight();
  }
}