How to resize the 3D view?

We are creating software that combines swing and xith3d. The basic window layout is split into two. On the left is a (swing) tree view of some components (left black in the image) and on the right is some toolbars on top and then a tabbed pane where the 3D view is.

How do we make the 3D view resize itself when the user changes the window size? Currently, when the user changes the window size the panel adjusts its size correctly but the 3DCanvas (created with RenderPeer.makeCanvas) stays at fixed size (the resolution specified at creation). So if the window size is grown the 3D view stays in the center and leaves gray empty space around it. We’d like to have the 3D fill the panel at all times. How can we achieve this?

http://www.hut.fi/~enuuros/sshot01.png

Do you add your (Xith3d) Canvas3D to a JFrame?
I use an AWT Frame to hold my Xith3d’s Canas3D in it, next to several Swing J-components.
Resizing the Frame works: the Canvas3D resizes correctly. However if I resize some Swing components from within the application, the Canvas3D keeps its old size like in your example. Then a Frame.validate() does the trick for me: the Canvas3D then fits itself to the other components, like it should be.