当我在Java3D中调整窗口大小时，屏幕变为空白

Question

每当我调整窗口大小时，它都会变成空白，形状消失。 我尝试添加：Toolkit.getDefaultToolkit（）。sync（）;刷新画布但它没有用。 有谁知道这是什么问题？

这是代码：

public class test2 extends JFrame  {

    static float x;
    static float y;
    static float z;


// Setup a SimpleUniverse by referenching a Canvas3D
    static GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration();
    Canvas3D canvas = new Canvas3D(config);

    // Creation du Canvas 3D
    RefreshCanvas3D canvas3D =
        new RefreshCanvas3D(config);

    class RefreshCanvas3D extends Canvas3D {
        public RefreshCanvas3D(GraphicsConfiguration config) {
          super(config);
        }
        public void paint(Graphics g) {
          super.paint(g);
          Toolkit.getDefaultToolkit().sync();
        }
      }

    //Build View
  protected BranchGroup buildViewBranch(Canvas3D c) {

        BranchGroup viewBranch = new BranchGroup();
        Transform3D viewXfm = new Transform3D();
        viewXfm.set(new Vector3f(0.0f, 0.0f, 5.0f));
        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;
      }
  //Build branchgroup 
  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));
        TransformGroup rotationGroup = new TransformGroup(rotateCube);
        contentBranch.addChild(rotationGroup);
        rotationGroup.addChild(shape);
        return contentBranch;
        }
  //create a container box
   protected Node buildShape(float x, float y, float z) {
        Appearance app = new Appearance();
        //Create the polygon attributes
        PolygonAttributes polyAttr = new PolygonAttributes();
        //Set them so that the draw mode is polygon line
        polyAttr.setPolygonMode(PolygonAttributes.CULL_BACK);

        app.setPolygonAttributes(polyAttr);
        Box containerBox = new Box( x, y, z, app);
        return containerBox;
      }


  static Box addProductBox(Float x1, Float y1, Float z1, Color3f c1, Color3f c2)
        {
            Appearance app = new Appearance();

            Color3f color = new Color3f(Color.yellow);
            Color3f black = new Color3f(Color.lightGray );
            Color3f white = new Color3f(Color.lightGray);
            Material mat=new Material(color, black, color, white, 70f);
            mat.setCapability(Material.SPECULAR);
            mat.setDiffuseColor(c1);
            mat.setSpecularColor(c2);
            mat.setShininess(6.0f);
            app.setMaterial(mat);
            Box box = new Box(x1, y1, z1, app);
            return box;
            }

     public test2(float x, float y , float z) {
        VirtualUniverse myUniverse = new VirtualUniverse();
        Locale myLocale = new Locale(myUniverse);

        BranchGroup nodeRoot = new BranchGroup();
        nodeRoot=buildContentBranch(buildShape(x, y, z));
        Shape3D backShape = ((Box) buildShape(x, y, z)).getShape(Box.BACK);
        TriangleStripArray geo = (TriangleStripArray) backShape.getGeometry();

         int rr = 2;
         float[] position = new float[3];
         geo.getCoordinates(rr, position);
          Vector3f pp = new Vector3f (position[0],position[1], position[2]);

                Transform3D transform = new Transform3D();
                transform.setTranslation(pp);
                Box ProductBox = addProductBox(0.1f,0.1f,0.1f,
                          new Color3f(0.7f, .15f, .15f), new Color3f(0.7f, .15f, .15f));

                Transform3D rotateCube = new Transform3D();
                rotateCube.set(new AxisAngle4d(1.0, 1.0, 0.0, Math.PI / 4.0));
                TransformGroup rotationGroup = new TransformGroup(rotateCube);
                TransformGroup TranslateGroup = new TransformGroup(transform);
                TranslateGroup.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
                rotationGroup.addChild(ProductBox);
                TranslateGroup.addChild(rotationGroup);
                nodeRoot.addChild(TranslateGroup);

     myLocale.addBranchGraph(nodeRoot);
        setTitle("Container Loading");
            setSize(800,800);
            setLayout(new BorderLayout());
            add("Center", canvas);
            setVisible(true);
            myLocale.addBranchGraph(buildViewBranch(canvas));
        }


    public static void main(String[] args) {

            java.awt.EventQueue.invokeLater(new Runnable() {
                 public void run() {
                     new test2(x, y , z);
                 }
          });



      }
}