大家看这个程序，为什么没有图象输出？

[wwhui]

import java.applet.Applet;
import java.awt.*;
import javax.media.j3d.*;
import javax.vecmath.*;
import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.behaviors.mouse.MouseRotate;
import com.sun.j3d.utils.universe.*;


public class threeface extends Applet {
BranchGroup createSceneGraph(){
BranchGroup objroot=new BranchGroup();

float[] vert={
0.0f,0.0f,0.0f,0.0f,0.0f,0.5f,
0.5f,0.0f,0.0f,0.0f,0.5f,0.0f
};
float[] color={
1.0f,0.0f,0.0f,0.0f,1.0f,0.0f,
0.0f,0.0f,1.0f,0.0f,1.0f,1.0f,

};
int[] indices={
0,1,2,1,0,3,3,2,1,2,0,3,

};
int[] colorindices={
0,0,0,1,1,1,
2,2,2,3,3,3,
};
IndexedTriangleArray tri=new IndexedTriangleArray(vert.length,
TriangleArray.COORDINATES|TriangleArray.COLOR_3,indices.length);
tri.setCoordinate(0, vert);
tri.setColor(0, color);
tri.setCoordinateIndices(0, indices);
tri.setColorIndices(0, colorindices);
Shape3D shape=new Shape3D();
shape.setGeometry(tri);
TransformGroup objtrans=new TransformGroup();
objtrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
objtrans.setCapability(TransformGroup.ALLOW_TRANSFORM_READ);
objtrans.addChild(shape);
objroot.addChild(objtrans);
BoundingSphere bounds=new BoundingSphere(new Point3d(0,0,0),100);
Color3f bgcolor=new Color3f(1.0f,1.0f,1.0f);
Background bg=new Background(bgcolor);
bg.setApplicationBounds(bounds);
objroot.addChild(bg);
objroot.compile();
return objroot;
}
public threeface(){
setLayout(new BorderLayout());
GraphicsConfiguration config=SimpleUniverse.getPreferredConfiguration();
Canvas3D c=new Canvas3D(config);
add("Center",c);
BranchGroup scene=createSceneGraph();
SimpleUniverse u=new SimpleUniverse(c);
u.getViewingPlatform().setNominalViewingTransform();
u.addBranchGraph(scene);
}
public static void main(String[] args){
new MainFrame(new threeface(),200,200);
}
}

[wwhui]

自己顶下.