spheremotion.java

JAVA网络三维技术3D的设计与实现

package Java3DApplet;
import java.applet.Applet;
import java.awt.BorderLayout;
import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.geometry.Sphere;
import com.sun.j3d.utils.universe.*;
import javax.media.j3d.*;
import javax.vecmath.*;
import java.util.Enumeration;

public class SphereMotion extends Applet {

    // Flag indicates whether to use directional or point light
    // This flag is set based on command line argument
    private static boolean usePointLights = true;

    public BranchGroup createSceneGraph(SimpleUniverse u) {
        Color3f eColor    = new Color3f(0.0f, 0.0f, 0.0f);
        Color3f sColor    = new Color3f(1.0f, 1.0f, 1.0f);
        Color3f objColor  = new Color3f(0.6f, 0.6f, 0.6f);
        Color3f lColor1   = new Color3f(1.0f, 0.0f, 0.0f);
        Color3f lColor2   = new Color3f(0.0f, 1.0f, 0.0f);
        Color3f alColor   = new Color3f(0.2f, 0.2f, 0.2f);
        Color3f bgColor   = new Color3f(0.05f, 0.05f, 0.2f);

        Transform3D t;

        // Create the root of the branch graph
        BranchGroup objRoot = new BranchGroup();

        // Create a Transformgroup to scale all objects so they
        // appear in the scene.
        TransformGroup objScale = new TransformGroup();
        Transform3D t3d = new Transform3D();
        t3d.setScale(0.4);
        objScale.setTransform(t3d);
        objRoot.addChild(objScale);

        // Create a bounds for the background and lights
        BoundingSphere bounds =
            new BoundingSphere(new Point3d(0.0,0.0,0.0), 100.0);

        // Set up the background
        Background bg = new Background(bgColor);
        bg.setApplicationBounds(bounds);
        objScale.addChild(bg);

        // Create a Sphere object, generate one copy of the sphere,
        // and add it into the scene graph.
        Material m = new Material(objColor, eColor, objColor, sColor, 100.0f);
        Appearance a = new Appearance();
        m.setLightingEnable(true);
        a.setMaterial(m);
        Sphere sph = new Sphere(1.0f, Sphere.GENERATE_NORMALS, 80, a);
        objScale.addChild(sph);

        // Create the transform group node for the each light and initialize
        // it to the identity.  Enable the TRANSFORM_WRITE capability so that
        // our behavior code can modify it at runtime.  Add them to the root
        // of the subgraph.
        TransformGroup l1RotTrans = new TransformGroup();
        l1RotTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
        objScale.addChild(l1RotTrans);

        TransformGroup l2RotTrans = new TransformGroup();
        l2RotTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
        objScale.addChild(l2RotTrans);

        // Create transformations for the positional lights
        t = new Transform3D();
        Vector3d lPos1 =  new Vector3d(0.0, 0.0, 2.0);
        t.set(lPos1);
        TransformGroup l1Trans = new TransformGroup(t);
        l1RotTrans.addChild(l1Trans);

        t = new Transform3D();
        Vector3d lPos2 = new Vector3d(0.5, 0.8, 2.0);
        t.set(lPos2);
        TransformGroup l2Trans = new TransformGroup(t);
        l2RotTrans.addChild(l2Trans);

        // Create Geometry for point lights
        ColoringAttributes caL1 = new ColoringAttributes();
        ColoringAttributes caL2 = new ColoringAttributes();
        caL1.setColor(lColor1);
        caL2.setColor(lColor2);
        Appearance appL1 = new Appearance();
        Appearance appL2 = new Appearance();
        appL1.setColoringAttributes(caL1);
        appL2.setColoringAttributes(caL2);
        l1Trans.addChild(new Sphere(0.05f, appL1));
        l2Trans.addChild(new Sphere(0.05f, appL2));

        // Create lights
        AmbientLight aLgt = new AmbientLight(alColor);

        Light lgt1;
        Light lgt2;

        if (usePointLights) {
            Point3f lPoint  = new Point3f(0.0f, 0.0f, 0.0f);
            Point3f atten = new Point3f(1.0f, 0.0f, 0.0f);
            lgt1 = new PointLight(lColor1, lPoint, atten);
            lgt2 = new PointLight(lColor2, lPoint, atten);
        }
        else {
            Vector3f lDirect1 = new Vector3f(lPos1);
            Vector3f lDirect2 = new Vector3f(lPos2);
            lDirect1.negate();
            lDirect2.negate();
            lgt1 = new DirectionalLight(lColor1, lDirect1);
            lgt2 = new DirectionalLight(lColor2, lDirect2);
        }

        // Set the influencing bounds
        aLgt.setInfluencingBounds(bounds);
        lgt1.setInfluencingBounds(bounds);
        lgt2.setInfluencingBounds(bounds);

        // Add the lights into the scene graph
        objScale.addChild(aLgt);
        l1Trans.addChild(lgt1);
        l2Trans.addChild(lgt2);

        // Create a new Behavior object that will perform the desired
        // operation on the specified transform object and add it into the
        // scene graph.
        Transform3D yAxis = new Transform3D();
        Alpha rotor1Alpha = new Alpha(-1, Alpha.INCREASING_ENABLE,
                                     0, 0,
                                     4000, 0, 0,
                                     0, 0, 0);
        RotationInterpolator rotator1 =
            new RotationInterpolator(rotor1Alpha,
                                     l1RotTrans,
                                     yAxis,
                                     0.0f, (float) Math.PI*2.0f);
        rotator1.setSchedulingBounds(bounds);
        l1RotTrans.addChild(rotator1);

        // Create a new Behavior object that will perform the desired
        // operation on the specified transform object and add it into the
        // scene graph.
        Alpha rotor2Alpha = new Alpha(-1, Alpha.INCREASING_ENABLE,
                                     0, 0,
                                     1000, 0, 0,
                                     0, 0, 0);
        RotationInterpolator rotator2 =
            new RotationInterpolator(rotor2Alpha,
                                     l2RotTrans,
                                     yAxis,
                                     0.0f, 0.0f);
        bounds = new BoundingSphere(new Point3d(0.0,0.0,0.0), 100.0);
        rotator2.setSchedulingBounds(bounds);
        l2RotTrans.addChild(rotator2);

        // Create a position interpolator and attach it to the view
        // platform
        TransformGroup vpTrans =
            u.getViewingPlatform().getViewPlatformTransform();
        Transform3D axisOfTranslation = new Transform3D();
        Alpha transAlpha = new Alpha(-1,
                                      Alpha.INCREASING_ENABLE |
                                      Alpha.DECREASING_ENABLE,
                                      0, 0,
                                      5000, 0, 0,
                                      5000, 0, 0);
        axisOfTranslation.rotY(-Math.PI/2.0);
        PositionInterpolator translator =
            new PositionInterpolator(transAlpha,
                                     vpTrans,
                                     axisOfTranslation,
                                     2.0f, 3.5f);
        translator.setSchedulingBounds(bounds);
        objScale.addChild(translator);

        // Let Java 3D perform optimizations on this scene graph.
        objRoot.compile();

        return objRoot;
    }

    public SphereMotion() {
        setLayout(new BorderLayout());
        Canvas3D c = new Canvas3D(null);
        add("Center", c);

        SimpleUniverse u = new SimpleUniverse(c);
        BranchGroup scene = createSceneGraph(u);

        // This will move the ViewPlatform back a bit so the
        // objects in the scene can be viewed.
        u.getViewingPlatform().setNominalViewingTransform();

        u.addBranchGraph(scene);
    }

    //
    // The following allows SphereMotion to be run as an application
    // as well as an applet
    //
    public static void main(String[] args) {
        // Parse the Input Arguments
        String usage = "Usage: java SphereMotion [-point | -dir]";
        for (int i = 0; i < args.length; i++) {
            if (args[i].startsWith("-")) {
                if (args[i].equals("-point")) {
                    System.out.println("Using point lights");
                    usePointLights = true;
                }
                else if (args[i].equals("-dir")) {
                    System.out.println("Using directional lights");
                    usePointLights = false;
                }
                else {
                    System.out.println(usage);
                    System.exit(0);
                }
            }
            else {
                System.out.println(usage);
                System.exit(0);
            }
        }

        new MainFrame(new SphereMotion(), 640, 480);
    }
}