SimpleLOD.java Source code

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Here is the source code for SimpleLOD.java

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/*
Essential Java 3D Fast
    
Ian Palmer
    
Publisher: Springer-Verlag
    
ISBN: 1-85233-394-4
    
*/

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

import javax.media.j3d.AmbientLight;
import javax.media.j3d.Appearance;
import javax.media.j3d.BoundingLeaf;
import javax.media.j3d.BoundingSphere;
import javax.media.j3d.BranchGroup;
import javax.media.j3d.Canvas3D;
import javax.media.j3d.DirectionalLight;
import javax.media.j3d.DistanceLOD;
import javax.media.j3d.Locale;
import javax.media.j3d.Material;
import javax.media.j3d.PhysicalBody;
import javax.media.j3d.PhysicalEnvironment;
import javax.media.j3d.Switch;
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.Vector3f;

import com.sun.j3d.utils.behaviors.keyboard.KeyNavigatorBehavior;
import com.sun.j3d.utils.geometry.Cylinder;

/**
 * This uses three resolutions of a cylinder to demonstrate the operation of a
 * level of detail node.
 * 
 * @author I.J.Palmer
 * @version 1.0
 */
public class SimpleLOD extends Frame implements ActionListener {
    protected Canvas3D myCanvas3D = new Canvas3D(null);

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

    protected BoundingSphere bounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0), 100.0);

    /**
     * Build the view branch of the scene graph. In this case a key navigation
     * utility object is created and associated with the view transform so that
     * the view can be changed via the keyboard.
     * 
     * @return BranchGroup that is the root of the view branch
     */
    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);
        viewXfmGroup.setCapability(TransformGroup.ALLOW_TRANSFORM_READ);
        viewXfmGroup.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
        BoundingSphere movingBounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0), 100.0);
        BoundingLeaf boundLeaf = new BoundingLeaf(movingBounds);
        ViewPlatform myViewPlatform = new ViewPlatform();
        viewXfmGroup.addChild(boundLeaf);
        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);

        KeyNavigatorBehavior keyNav = new KeyNavigatorBehavior(viewXfmGroup);
        keyNav.setSchedulingBounds(movingBounds);
        viewBranch.addChild(keyNav);

        return viewBranch;
    }

    /**
     * Add some lights to the scene graph
     * 
     * @param b
     *            BranchGroup that the lights are added to
     */
    protected void addLights(BranchGroup b) {
        Color3f ambLightColour = new Color3f(0.5f, 0.5f, 0.5f);
        AmbientLight ambLight = new AmbientLight(ambLightColour);
        ambLight.setInfluencingBounds(bounds);
        Color3f dirLightColour = new Color3f(1.0f, 1.0f, 1.0f);
        Vector3f dirLightDir = new Vector3f(-1.0f, -1.0f, -1.0f);
        DirectionalLight dirLight = new DirectionalLight(dirLightColour, dirLightDir);
        dirLight.setInfluencingBounds(bounds);
        b.addChild(ambLight);
        b.addChild(dirLight);
    }

    /**
     * Build the content branch for the scene graph This creates three
     * cylinders, each with a different resolution. These are then used with a
     * LOD node to implement a crude level of detail.
     * 
     * @return BranchGroup that is the root of the content
     */
    protected BranchGroup buildContentBranch() {
        //Create the appearance
        Appearance app = new Appearance();
        Color3f ambientColour = new Color3f(1.0f, 1.0f, 0.0f);
        Color3f emissiveColour = new Color3f(0.0f, 0.0f, 0.0f);
        Color3f specularColour = new Color3f(1.0f, 1.0f, 1.0f);
        Color3f diffuseColour = new Color3f(1.0f, 1.0f, 0.0f);
        float shininess = 20.0f;
        app.setMaterial(new Material(ambientColour, emissiveColour, diffuseColour, specularColour, shininess));
        //Make the switch node that is to used with the LOD
        //and make it writable
        Switch LODswitch = new Switch();
        LODswitch.setCapability(Switch.ALLOW_SWITCH_WRITE);
        //Add the three cylinders
        LODswitch.addChild(new Cylinder(1.0f, 1.0f, Cylinder.GENERATE_NORMALS, 10, 10, app));
        LODswitch.addChild(new Cylinder(1.0f, 1.0f, Cylinder.GENERATE_NORMALS, 5, 5, app));
        LODswitch.addChild(new Cylinder(1.0f, 1.0f, Cylinder.GENERATE_NORMALS, 3, 3, app));
        //Define the distances for the LOD
        float[] LODdistances = { 5.0f, 10.0f, 15.0f };
        DistanceLOD myLOD = new DistanceLOD(LODdistances, new Point3f(0.0f, 0.0f, 0.0f));
        myLOD.setSchedulingBounds(bounds);
        //Add the switch to the LOD
        myLOD.addSwitch(LODswitch);
        BranchGroup contentBranch = new BranchGroup();
        contentBranch.addChild(myLOD);
        addLights(contentBranch);

        contentBranch.addChild(LODswitch);
        return contentBranch;

    }

    /**
     * Use the action event of the exit button to end the application.
     */
    public void actionPerformed(ActionEvent e) {
        dispose();
        System.exit(0);
    }

    public SimpleLOD() {
        VirtualUniverse myUniverse = new VirtualUniverse();
        Locale myLocale = new Locale(myUniverse);
        myLocale.addBranchGraph(buildViewBranch(myCanvas3D));
        myLocale.addBranchGraph(buildContentBranch());
        setTitle("SimpleLOD");
        setSize(400, 400);
        setLayout(new BorderLayout());
        Panel bottom = new Panel();
        bottom.add(exitButton);
        add(BorderLayout.CENTER, myCanvas3D);
        add(BorderLayout.SOUTH, bottom);
        exitButton.addActionListener(this);
        setVisible(true);
    }

    public static void main(String[] args) {
        SimpleLOD sl = new SimpleLOD();
    }
}