Java3D, отрендеренную картинку нужно сохранять в файл на диск, а не отображать на экране

import java.applet.Applet;
import java.awt.BorderLayout;
import java.awt.Frame;
import java.awt.event.*;
import com.sun.j3d.utils.applet.MainFrame; 
import com.sun.j3d.utils.universe.*; 
import com.sun.j3d.utils.geometry.ColorCube;
import javax.media.j3d.*;
import javax.vecmath.*;
 
public class HelloJava3Da extends Applet {
public HelloJava3Da() {
setLayout(new BorderLayout());
Canvas3D canvas3D = new Canvas3D(null);
add('Center', canvas3D);
BranchGroup scene = createSceneGraph();
SimpleUniverse simpleU = new SimpleUniverse(canvas3D);
simpleU.getViewingPlatform().setNominalViewingTransform();
simpleU.addBranchGraph(scene);
}
public BranchGroup createSceneGraph() {
BranchGroup objRoot = new BranchGroup();
objRoot.addChild(new ColorCube(0.4));
return objRoot;
}
public static void main(String[] args) {
Frame frame = new MainFrame(new HelloJava3Da(), 256, 256);
}
}

Image image = Jimi.getImage('myImage.PSD');
Jimi.putImage(image, 'myImage.PNG');

canvas3D = new Canvas3D(null);

import java.awt.GraphicsConfiguration;
import java.awt.image.BufferedImage;
import javax.media.j3d.*;
import javax.vecmath.*;
 
public class OffScreenCanvas3D extends Canvas3D
{
    public OffScreenCanvas3D(GraphicsConfiguration graphicsConfiguration, boolean offScreen)
    {
        super(graphicsConfiguration, offScreen);
    }
 
    public BufferedImage doRender(int width, int height)
    {
        BufferedImage bImage =
            new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);//TYPE_3BYTE_BGR);// .TYPE_INT_ARGB);//
 
        ImageComponent2D buffer =
            new ImageComponent2D(ImageComponent.FORMAT_RGB, bImage);
 
        setOffScreenBuffer(buffer);
        renderOffScreenBuffer();
        waitForOffScreenRendering();
        bImage = getOffScreenBuffer().getImage();
 
        return bImage;
    }
 
    public void postSwap()
    {
        // No-op since we always wait for off-screen rendering to complete
    }
}

BufferedImage bImage = offScreenCanvas3D_m.doRender(width, height);