This Java tip renders a PointArray in Immediate Mode and outputs the FPS for the rendering.

 import java.applet.Applet;
import java.awt.BorderLayout;
import java.awt.GraphicsConfigTemplate;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.io.File;
import java.net.URL;

import javax.media.j3d.Appearance;
import javax.media.j3d.AudioDevice;
import javax.media.j3d.Background;
import javax.media.j3d.BoundingSphere;
import javax.media.j3d.Bounds;
import javax.media.j3d.BranchGroup;
import javax.media.j3d.Canvas3D;
import javax.media.j3d.ColoringAttributes;
import javax.media.j3d.DirectionalLight;
import javax.media.j3d.GeometryArray;
import javax.media.j3d.GraphicsConfigTemplate3D;
import javax.media.j3d.GraphicsContext3D;
import javax.media.j3d.Group;
import javax.media.j3d.Light;
import javax.media.j3d.Locale;
import javax.media.j3d.Material;
import javax.media.j3d.PhysicalBody;
import javax.media.j3d.PhysicalEnvironment;
import javax.media.j3d.PointArray;
import javax.media.j3d.PointAttributes;
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.Color3f;
import javax.vecmath.Point3d;
import javax.vecmath.Point3f;
import javax.vecmath.Vector3d;

import com.sun.j3d.audioengines.javasound.JavaSoundMixer;
import com.sun.j3d.utils.applet.MainFrame;

/**
 * This example renders a PointArray in Immediate Mode and outputs the FPS for
 * the rendering.
 * 
 * @see ImmediateCanvas3D.java for the rendering code.
 */
public class ImmediateTest extends Java3dApplet {
  private static int m_kWidth = 400;

  private static int m_kHeight = 400;

  public ImmediateTest() {
    // we need to create the minimal Java 3D scenegraph
    // structure to the View rendering loop.

    // create the VirtualUniverse
    m_Universe = createVirtualUniverse();

    // create a Locale
    Locale locale = createLocale(m_Universe);

    // create the ViewPlatform and add to the Locale
    ViewPlatform vp = createViewPlatform();
    BranchGroup viewBranchGroup = createViewBranchGroup(null, vp);
    addViewBranchGroup(locale, viewBranchGroup);

    // create the View and attach to the ViewPlatform
    createView(vp);
  }

  protected Canvas3D createCanvas3D() {
    // overidden this method to create a custom
    // Canvas3D that will implement the Immediate Mode rendering
    GraphicsConfigTemplate3D gc3D = new GraphicsConfigTemplate3D();
    gc3D.setSceneAntialiasing(GraphicsConfigTemplate.PREFERRED);
    GraphicsDevice gd[] = GraphicsEnvironment.getLocalGraphicsEnvironment()
        .getScreenDevices();

    ImmediateCanvas3D c3d = new ImmediateCanvas3D(gd[0]
        .getBestConfiguration(gc3D));
    c3d.setSize(getCanvas3dWidth(c3d), getCanvas3dHeight(c3d));

    return (Canvas3D) c3d;
  }

  public static void main(String[] args) {
    ImmediateTest immediateTest = new ImmediateTest();
    immediateTest.saveCommandLineArguments(args);

    new MainFrame(immediateTest, m_kWidth, m_kHeight);
  }
}

class ImmediateCanvas3D extends Canvas3D {
  private long m_nRender = 0;

  private long m_StartTime = 0;

  private static final int nGridSize = 50;

  private static final int m_kReportInterval = 50;

  private PointArray m_PointArray = new PointArray(nGridSize * nGridSize,
      GeometryArray.COORDINATES);

  private Transform3D m_t3d = new Transform3D();

  private float m_rot = 0.0f;

  ImmediateCanvas3D(java.awt.GraphicsConfiguration graphicsConfiguration) {
    super(graphicsConfiguration);

    // create the PointArray that we will be rendering
    int nPoint = 0;

    for (int n = 0; n < nGridSize; n++) {
      for (int i = 0; i < nGridSize; i++) {
        Point3f point = new Point3f(n - nGridSize / 2, i - nGridSize
            / 2, 0.0f);
        m_PointArray.setCoordinate(nPoint++, point);
      }
    }
  }

  public void renderField(int fieldDesc) {
    super.renderField(fieldDesc);

    GraphicsContext3D g = getGraphicsContext3D();

    // first time initialization
    if (m_nRender == 0) {
      // set the start time
      m_StartTime = System.currentTimeMillis();

      // add a light to the graphics context
      DirectionalLight light = new DirectionalLight();
      light.setEnable(true);
      g.addLight((Light) light);

      // create the material for the points
      Appearance a = new Appearance();
      Material mat = new Material();
      mat.setLightingEnable(true);
      mat.setAmbientColor(0.5f, 1.0f, 1.0f);
      a.setMaterial(mat);
      a.setColoringAttributes(new ColoringAttributes(1.0f, 0.5f, 0.5f,
          ColoringAttributes.NICEST));

      // enlarge the points
      a.setPointAttributes(new PointAttributes(4, true));

      // make the appearance current in the graphics context
      g.setAppearance(a);
    }

    // set the current transformation for the graphics context
    g.setModelTransform(m_t3d);

    // finally render the PointArray
    g.draw(m_PointArray);

    // calculate and display the Frames Per Second for the
    // Immediate Mode rendering of the PointArray
    m_nRender++;

    if ((m_nRender % m_kReportInterval) == 0) {
      float fps = (float) 1000.0f
          / ((System.currentTimeMillis() - m_StartTime) / (float) m_kReportInterval);
      System.out.println("FPS:\t" + fps);

      m_StartTime = System.currentTimeMillis();
    }
  }

  public void preRender() {
    super.preRender();

    // update the model transformation to rotate the PointArray
    // about the Y axis.
    m_rot += 0.1;
    m_t3d.rotY(m_rot);

    // move the transform back so we can see the points
    m_t3d.setTranslation(new Vector3d(0.0, 0.0, -20.0));

    // scale the transformation down so we can see all of the points
    m_t3d.setScale(0.3);

    // force a paint (will call renderField)
    paint(getGraphics());
  }
}

/*******************************************************************************
 * Copyright (C) 2001 Daniel Selman
 * 
 * First distributed with the book "Java 3D Programming" by Daniel Selman and
 * published by Manning Publications. http://manning.com/selman
 * 
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, version 2.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 * 
 * The license can be found on the WWW at: http://www.fsf.org/copyleft/gpl.html
 * 
 * Or by writing to: Free Software Foundation, Inc., 59 Temple Place - Suite
 * 330, Boston, MA 02111-1307, USA.
 * 
 * Authors can be contacted at: Daniel Selman: This email address is being protected from spambots. You need JavaScript enabled to view it.
 * 
 * If you make changes you think others would like, please contact one of the
 * authors or someone at the www.j3d.org web site.
 ******************************************************************************/

//*****************************************************************************
/**
 * Java3dApplet
 * 
 * Base class for defining a Java 3D applet. Contains some useful methods for
 * defining views and scenegraphs etc.
 * 
 * @author Daniel Selman
 * @version 1.0
 */
//*****************************************************************************

abstract class Java3dApplet extends Applet {
  public static int m_kWidth = 300;

  public static int m_kHeight = 300;

  protected String[] m_szCommandLineArray = null;

  protected VirtualUniverse m_Universe = null;

  protected BranchGroup m_SceneBranchGroup = null;

  protected Bounds m_ApplicationBounds = null;

  //  protected com.tornadolabs.j3dtree.Java3dTree m_Java3dTree = null;

  public Java3dApplet() {
  }

  public boolean isApplet() {
    try {
      System.getProperty("user.dir");
      System.out.println("Running as Application.");
      return false;
    } catch (Exception e) {
    }

    System.out.println("Running as Applet.");
    return true;
  }

  public URL getWorkingDirectory() throws java.net.MalformedURLException {
    URL url = null;

    try {
      File file = new File(System.getProperty("user.dir"));
      System.out.println("Running as Application:");
      System.out.println("   " + file.toURL());
      return file.toURL();
    } catch (Exception e) {
    }

    System.out.println("Running as Applet:");
    System.out.println("   " + getCodeBase());

    return getCodeBase();
  }

  public VirtualUniverse getVirtualUniverse() {
    return m_Universe;
  }

  //public com.tornadolabs.j3dtree.Java3dTree getJ3dTree() {
  //return m_Java3dTree;
  //  }

  public Locale getFirstLocale() {
    java.util.Enumeration e = m_Universe.getAllLocales();

    if (e.hasMoreElements() != false)
      return (Locale) e.nextElement();

    return null;
  }

  protected Bounds getApplicationBounds() {
    if (m_ApplicationBounds == null)
      m_ApplicationBounds = createApplicationBounds();

    return m_ApplicationBounds;
  }

  protected Bounds createApplicationBounds() {
    m_ApplicationBounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0),
        100.0);
    return m_ApplicationBounds;
  }

  protected Background createBackground() {
    Background back = new Background(new Color3f(0.9f, 0.9f, 0.9f));
    back.setApplicationBounds(createApplicationBounds());
    return back;
  }

  public void initJava3d() {
    //  m_Java3dTree = new com.tornadolabs.j3dtree.Java3dTree();
    m_Universe = createVirtualUniverse();

    Locale locale = createLocale(m_Universe);

    BranchGroup sceneBranchGroup = createSceneBranchGroup();

    ViewPlatform vp = createViewPlatform();
    BranchGroup viewBranchGroup = createViewBranchGroup(
        getViewTransformGroupArray(), vp);

    createView(vp);

    Background background = createBackground();

    if (background != null)
      sceneBranchGroup.addChild(background);

    //    m_Java3dTree.recursiveApplyCapability(sceneBranchGroup);
    //  m_Java3dTree.recursiveApplyCapability(viewBranchGroup);

    locale.addBranchGraph(sceneBranchGroup);
    addViewBranchGroup(locale, viewBranchGroup);

    onDoneInit();
  }

  protected void onDoneInit() {
    //  m_Java3dTree.updateNodes(m_Universe);
  }

  protected double getScale() {
    return 1.0;
  }

  public TransformGroup[] getViewTransformGroupArray() {
    TransformGroup[] tgArray = new TransformGroup[1];
    tgArray[0] = new TransformGroup();

    // move the camera BACK a little...
    // note that we have to invert the matrix as
    // we are moving the viewer
    Transform3D t3d = new Transform3D();
    t3d.setScale(getScale());
    t3d.setTranslation(new Vector3d(0.0, 0.0, -20.0));
    t3d.invert();
    tgArray[0].setTransform(t3d);

    return tgArray;
  }

  protected void addViewBranchGroup(Locale locale, BranchGroup bg) {
    locale.addBranchGraph(bg);
  }

  protected Locale createLocale(VirtualUniverse u) {    return new Locale(u);
  }

  protected BranchGroup createSceneBranchGroup() {
    m_SceneBranchGroup = new BranchGroup();
    return m_SceneBranchGroup;
  }

  protected View createView(ViewPlatform vp) {
    View view = new View();

    PhysicalBody pb = createPhysicalBody();
    PhysicalEnvironment pe = createPhysicalEnvironment();

    AudioDevice audioDevice = createAudioDevice(pe);

    if (audioDevice != null) {
      pe.setAudioDevice(audioDevice);
      audioDevice.initialize();
    }

    view.setPhysicalEnvironment(pe);
    view.setPhysicalBody(pb);

    if (vp != null)

      view.attachViewPlatform(vp);

    view.setBackClipDistance(getBackClipDistance());
    view.setFrontClipDistance(getFrontClipDistance());

    Canvas3D c3d = createCanvas3D();
    view.addCanvas3D(c3d);
    addCanvas3D(c3d);

    return view;
  }

  protected PhysicalBody createPhysicalBody() {
    return new PhysicalBody();
  }

  protected AudioDevice createAudioDevice(PhysicalEnvironment pe) {
    JavaSoundMixer javaSoundMixer = new JavaSoundMixer(pe);

    if (javaSoundMixer == null)
      System.out.println("create of audiodevice failed");

    return javaSoundMixer;
  }

  protected PhysicalEnvironment createPhysicalEnvironment() {
    return new PhysicalEnvironment();
  }

  protected float getViewPlatformActivationRadius() {
    return 100;
  }

  protected ViewPlatform createViewPlatform() {
    ViewPlatform vp = new ViewPlatform();
    vp.setViewAttachPolicy(View.RELATIVE_TO_FIELD_OF_VIEW);
    vp.setActivationRadius(getViewPlatformActivationRadius());

    return vp;
  }

  protected Canvas3D createCanvas3D() {
    GraphicsConfigTemplate3D gc3D = new GraphicsConfigTemplate3D();
    gc3D.setSceneAntialiasing(GraphicsConfigTemplate.PREFERRED);
    GraphicsDevice gd[] = GraphicsEnvironment.getLocalGraphicsEnvironment()
        .getScreenDevices();

    Canvas3D c3d = new Canvas3D(gd[0].getBestConfiguration(gc3D));
    c3d.setSize(getCanvas3dWidth(c3d), getCanvas3dHeight(c3d));

    return c3d;
  }

  protected int getCanvas3dWidth(Canvas3D c3d) {
    return m_kWidth;
  }

  protected int getCanvas3dHeight(Canvas3D c3d) {
    return m_kHeight;
  }

  protected double getBackClipDistance() {
    return 100.0;
  }

  protected double getFrontClipDistance() {
    return 1.0;
  }

  protected BranchGroup createViewBranchGroup(TransformGroup[] tgArray,
      ViewPlatform vp) {
    BranchGroup vpBranchGroup = new BranchGroup();

    if (tgArray != null && tgArray.length > 0) {
      Group parentGroup = vpBranchGroup;
      TransformGroup curTg = null;

      for (int n = 0; n < tgArray.length; n++) {
        curTg = tgArray[n];
        parentGroup.addChild(curTg);
        parentGroup = curTg;
      }

      tgArray[tgArray.length - 1].addChild(vp);
    } else
      vpBranchGroup.addChild(vp);

    return vpBranchGroup;
  }

  protected void addCanvas3D(Canvas3D c3d) {
    setLayout(new BorderLayout());
    add(c3d, BorderLayout.CENTER);
    doLayout();
  }

  protected VirtualUniverse createVirtualUniverse() {
    return new VirtualUniverse();
  }

  protected void saveCommandLineArguments(String[] szArgs) {
    m_szCommandLineArray = szArgs;
  }

  protected String[] getCommandLineArguments() {
    return m_szCommandLineArray;
  }
}