diff --git a/java/org/artisanlogiciel/games/Display.java b/java/org/artisanlogiciel/games/Display.java
index 28b1a5a..8864592 100644
--- a/java/org/artisanlogiciel/games/Display.java
+++ b/java/org/artisanlogiciel/games/Display.java
@@ -56,7 +56,7 @@ public class Display extends JFrame
     LabyModel model;
     JPanel controlPanel;
     boolean autoSize;
-    //    MazeParamsFixed fixedParams = null;
+
     MazeParams params = null;
     
     Display(LabyModel model,int W, int H, MazeParams params)
@@ -100,8 +100,7 @@ public class Display extends JFrame
 
     void recreateModel()
     {
-	// recreate labyrinth TODO / FIXME
-	System.out.println("TODO recreateModel");
+	// recreate labyrinth
 	if (params != null)
 	    {
 		params = controler.getSettings().getParams();
@@ -109,9 +108,14 @@ public class Display extends JFrame
 		maze.resetWallsProvider(model);
 		model.setMazeListener(maze);
 
-		model.generateWithEntry(0, 0);
-		model.addEntryOrExit(-1, 0);
-		model.addEntryOrExit(params.getWidth(), params.getHeight() - 1);
+		// we are in GUI event thread, need to release it and do it outside.
+		new Thread() {
+		    public void run() {			
+			model.generateWithEntry(0, 0);
+			model.addEntryOrExit(-1, 0);
+			model.addEntryOrExit(params.getWidth(), params.getHeight() - 1);
+		    }
+		}.start();
 
 	    }
     }
@@ -158,9 +162,11 @@ public class Display extends JFrame
     void savePng()
     {
 	File file = new File("snapshot.png");
-	BufferedImage bi = new BufferedImage(this.getSize().width, this.getSize().height, BufferedImage.TYPE_INT_ARGB);
+	// BufferedImage bi = new BufferedImage(this.getSize().width, this.getSize().height, BufferedImage.TYPE_INT_ARGB);
+	BufferedImage bi = new BufferedImage(maze.getSize().width, maze.getSize().height, BufferedImage.TYPE_INT_ARGB);
         Graphics g = bi.createGraphics();
-        this.paint(g);
+        // this.paint(g);
+	maze.paint(g);
         g.dispose();
         try{
             ImageIO.write(bi,"png",file);
@@ -187,15 +193,18 @@ public class Display extends JFrame
 
 	void createSettingsGui()
 	{
-	    JButton buttonCreate = new JButton(labels.getString("create"));
-	    buttonCreate.addActionListener(new ActionListener()
+	    if ( params != null )
 		{
-		    public void actionPerformed(ActionEvent evt)
-		    {
-			recreateModel();
-		    }		    
-		});
-	    add(buttonCreate);
+		    JButton buttonCreate = new JButton(labels.getString("create"));
+		    buttonCreate.addActionListener(new ActionListener()
+			{
+			    public void actionPerformed(ActionEvent evt)
+			    {
+				recreateModel();
+			    }		    
+			});
+		    add(buttonCreate);
+		}
 	    if ( params != null )
 		{
 		    JLabel widthLabel = new JLabel(labels.getString("width"));
@@ -223,7 +232,7 @@ public class Display extends JFrame
 
     }
 
-    private class MazeParamsFixed implements MazeParams
+    private static class MazeParamsFixed implements MazeParams
     {
 	int width;
 	int height;
@@ -848,9 +857,7 @@ public class Display extends JFrame
         }
         else
         {
-            System.out.println("enter width height and maxdepth");
-            MazeParamEditor params = new MazeParamEditor(new File("lab"));
-            params.read(new Scanner(System.in));
+            MazeParamsFixed params = new MazeParamsFixed(new File("lab"),60,60,15);
             model = new LabyModel(params, new java.util.Random());
 
 	    setupDisplay(model,W,H,params);
diff --git a/java/org/artisanlogiciel/games/stl/Wall3d.java b/java/org/artisanlogiciel/games/stl/Wall3d.java
index a26ddc2..875f4a4 100644
--- a/java/org/artisanlogiciel/games/stl/Wall3d.java
+++ b/java/org/artisanlogiciel/games/stl/Wall3d.java
@@ -123,6 +123,9 @@ public class Wall3d
 
     }
 
+    /**
+       write triangles as stl text
+     **/
     public String toString()
     {
         String s = "";