请教!Java3D中的图形报错,请大侠帮我看看!!!!!

[lmjzw]

我的原代码如下:
package javaapp;

import java.applet.Applet;
import java.awt.BorderLayout;
import com.sun.j3d.utils.applet.JMainFrame;
import com.sun.j3d.utils.universe.*;
import javax.media.j3d.*;
import javax.vecmath.*;

public class MainFrame extends javax.swing.JFrame {

public BranchGroup createSceneGraph()
{
BranchGroup objRoot=new BranchGroup();
float vert[]={0.8f,0.8f,0.0f,-0.8f,0.8f,0.0f,0.5f,0.0f,0.0f,-0.5f,0.0f,0.0f,-0.8f,-0.8f,0.0f,0.8f,-0.8f,0.0f};
float color[]={0.0f,0.5f,1.0f,0.5f,0.0f,1.0f,0.0f,0.8f,0.2f,1.0f,0.0f,0.3f,0.0f,1.0f,0.3f,0.3f,0.8f,0.0f};
Shape3D shape=new Shape3D();
PointArray point=new PointArray(6,PointArray.COORDINATES|PointArray.COLOR_3);
point.setCoordinate(0,vert);
point.setColor(0,color);
shape.setGeometry(point);
objRoot.addChild(shape);
objRoot.compile();
return objRoot;
}
public MainFrame() {
Canvas3D c=new Canvas3D(null);
this.add("Center",c);
BranchGroup scene=createSceneGraph();
SimpleUniverse u=new SimpleUniverse(c);
u.getViewingPlatform().setNominalViewingTransform();
u.addBranchGraph(scene);

initComponents();
}


private void initComponents() {

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
pack();
}


// 变量声明 - 不进行修改
// 变量声明结束

}
错误如下(在运行时才报的):

************************************************************************
*** ERROR: Canvas3D constructed with a null GraphicsConfiguration
*** This will cause a NullPointerException in a subsequent release
************************************************************************


程序可以执行,但结果全是黑屏,什么效果都没有!

[lmjzw]

主项目文件如下:
/*
* Main.java
*
* Created on 2005年5月31日, 下午9:45
*/

package javaapp;
/**
*
* @author Administrator
*/
public class Main {

/** Creates a new instance of Main */
public Main() {
}

/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
MainFrame MFrame=new MainFrame();
MFrame.setSize(500, 300);
MFrame.setVisible(true);

}
});
}

}

[chenweionline]

汉没研究过java 3d，帮顶吧。