[Jython-users] newbie trying to convert HelloJava3Da to jython

[Jack M. <jma...@nc...>]

LIke the subject says, I'm new to jython AND java3D and I'm trying to get 
HelloJava3Da.java to run as jython code.  In fact, I'm still very new to 
python.  Basically I want to start playing around with jython using the 
java3d api so I started with a java example that compiles and opens a black 
window with a red square:
---------begin----------
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);
  }
}
---------end----------

This works just fine.  The most current version of my attempt at a conversion 
to jython looks like this:
---------begin----------
from java.applet import Applet
from java.awt import BorderLayout
from java.awt import Frame
from java.awt.event import *
from com.sun.j3d.utils.applet import MainFrame
from com.sun.j3d.utils.universe import *
from com.sun.j3d.utils.geometry import ColorCube
from javax.media.j3d import *
from javax.vecmath import *

class HelloJava3Da(Applet):
        def __init__(self):
#               setLayout(BorderLayout())
                canvas3D = Canvas3D(None)
#               add("center", canvas3D)
                myscene = self.createSceneGraph()
                simpleU =  SimpleUniverse(canvas3D)
                simpleU.getViewingPlatform().setNominalViewingTransform()
                simpleU.addBranchGraph(myscene)

        def createSceneGraph(self):
                objRoot = BranchGroup()
                objRoot.addChild(ColorCube(0.4))
                return objRoot

myhj = HelloJava3Da()
frame = MainFrame(myhj, 256, 256)
---------end----------
It actually runs without error and opens a window, but it is blank, not black 
with a big red square.  Notice the two lines that are commented out.  When I 
comment out the equivalent lines from the java program, I also get a blank 
window that looks the same.  The problem is when I uncomment the setLayout 
line I get:

Traceback (innermost last):
  File "HelloJava3a.py", line 26, in ?
  File "HelloJava3a.py", line 13, in __init__
NameError: setLayout

and when I uncomment the add line I get:

WARNING: Canvas3D constructed with a null GraphicsConfiguration.
Loading required GL library /usr/X11R6/lib/libGL.so.1.2.030402
Traceback (innermost last):
  File "HelloJava3a.py", line 26, in ?
  File "HelloJava3a.py", line 15, in __init__
NameError: add

I get the "WARNING" and the "Loading" line when the java program runs 
correctly.

I've tried changing around the import statements, and tried things like 
changing setLayout to java.awt.setLayout which doesn't work.  Telling me what 
is wrong would be great, but I'm really hoping someone can give me a short 
explaination of WHY it isn't working and what I should do to get it to work.  


Thanks for any help you can give,
-Jack