SimpleTransform.java Source code

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Here is the source code for SimpleTransform.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.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.Node;
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.Box;

/**
 * This program uses AWT buttons to allow the user to rotate an object. This is
 * achieved by altering the transform of a transform group.
 * 
 * @author I.J.Palmer
 * @version 1.0
 */
public class SimpleTransform extends Frame implements ActionListener {
    protected Canvas3D myCanvas3D = new Canvas3D(null);

    /** The exit button */
    protected Button exitButton = new Button("Exit");

    /** The rotate left button */
    protected Button leftButton = new Button("<-");

    /** The rotate right button */
    protected Button rightButton = new Button("->");

    /** The transform group used to rotate the shape */
    protected TransformGroup rotationGroup;

    /**
     * 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;
    }

    /**
     * Add some lights so that we can illuminate the scene. This adds one
     * ambient light to bring up the overall lighting level and one directional
     * shape to show the shape of the objects in the scene.
     * 
     * @param b
     *            BranchGroup that the lights are to be added to.
     */
    protected void addLights(BranchGroup b) {
        BoundingSphere bounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0), 100.0);
        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);
    }

    /**
     * This builds the content branch of our scene graph. The root of the shapes
     * supplied as a parameter is slightly tilted to reveal its 3D shape. It
     * also uses the addLights function to add some lights to the scene. The
     * group that the shape is added to has its capabilities set so that we can
     * read and write it.
     * 
     * @param shape
     *            Node that represents the geometry for the content
     * @return BranchGroup that is the root of the content branch
     */
    protected BranchGroup buildContentBranch(Node shape) {
        BranchGroup contentBranch = new BranchGroup();
        Transform3D rotateCube = new Transform3D();
        rotateCube.set(new AxisAngle4d(1.0, 1.0, 0.0, Math.PI / 4.0));
        rotationGroup = new TransformGroup(rotateCube);
        //Set the capabilities so that the transform can be accessed
        rotationGroup.setCapability(TransformGroup.ALLOW_TRANSFORM_READ);
        rotationGroup.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
        contentBranch.addChild(rotationGroup);
        rotationGroup.addChild(shape);
        addLights(contentBranch);
        return contentBranch;
    }

    /**
     * This defines the shapes used in the scene. It creates a simple cube using
     * a Box utility class.
     * 
     * @return Node that is the root of the shape hierarchy.
     */
    protected Node buildShape() {
        Appearance app = new Appearance();
        Color3f ambientColour = new Color3f(1.0f, 0.0f, 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, 0.0f, 0.0f);
        float shininess = 20.0f;
        app.setMaterial(new Material(ambientColour, emissiveColour, diffuseColour, specularColour, shininess));
        return new Box(2.0f, 2.0f, 2.0f, app);
    }

    /**
     * This processes the AWT events and performs the appropriate operations.
     * The exit button causes the program to terminate, the left button causes a
     * rotation to be applied to the shape's transformation to spin it to the
     * left and the right has the similar effect but to the right button.
     * 
     * @param e
     *            ActionEvent that has been performed
     */
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == exitButton) {
            dispose();
            System.exit(0);
        } else if (e.getSource() == leftButton) {
            //Create a temporary transform
            Transform3D temp = new Transform3D();
            //Read the transform from the shape
            rotationGroup.getTransform(temp);
            //Create a rotation that will be applied
            Transform3D tempDelta = new Transform3D();
            tempDelta.rotY(-0.3);
            //Apply the rotation
            temp.mul(tempDelta);
            //Write the value back into the scene graph
            rotationGroup.setTransform(temp);
        } else if (e.getSource() == rightButton) {
            //Do the same for the right rotation
            Transform3D temp = new Transform3D();
            rotationGroup.getTransform(temp);
            Transform3D tempDelta = new Transform3D();
            tempDelta.rotY(0.3);
            temp.mul(tempDelta);
            rotationGroup.setTransform(temp);
        }
    }

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

    public static void main(String[] args) {
        SimpleTransform st = new SimpleTransform();
    }
}