I just saw that Xith3D has the possibility of rendering Swing components as part of their scene graph (most likely by rendering the components to some kind of buffer first and than rendering that buffer to the screen) and I was wondering if something like that existed for JOGL?
(NB: I’m not interested in just dropping components on a JPanel, I really want them to be part of the scene so I can for example blend them with the scene that is being rendered).
There isn’t anything in the JOGL core that supports this. If you need 2D UI components overlaying your 3D, you could use the GLJPanel and make your Swing components translucent. In the forthcoming 1.1 b08 the GLJPanel should have improved performance and capabilities via hardware acceleration.
No I understand that this is not in the core, it was more a question if somebody knew of a similar thing that could be used with JOGL 
And having transparent Swing components is not exactly what I’m looking for but something much more integrated. It should be possible to paste the GUI on the side of a cube for all I care
I haven’t done this, but couldn’t you use a buffer from swing as a texture in JOGL? Then you could paint it as a decal on any part of your 3d scene?