That must be interesting.
Please post the reasons why you use a specific scenegraph instead of another.
Aviatrix3D and OpenMind have been voluntarily ommitted.
Please don’t flame.
Well, I use Xith3D because it’s what a guy who made Tribal Trouble recommended me to look at. And I found it great.
I didn’t succeed installing LWJGL the first time, so I threw it up. On the other side, Xith3D has a cool Installation Tutorial very easy to follow.
I’ve downloaded Java3D but found out it was dead and there was no Linux version. And I really needed Linux support.
jME, if I were to try… because it’s LWJGL based 
Cas
Java3D because I like the plans they are making for it in the future. I think it’s performance will match JOGL/LWJGL soon as well. But I don’t know. :-\
jME… I like where it’s at now with it’s functionality, future integration is planned with JOGL, (giving the choice of either LWJGL or JOGL for rendering), it’s very actively developed and has a great users forum just like this one.
Xith3D because I had a previous experience with Java3D, so switching was very easy.
I like the simplicity of it : a prototype game can be created in a matter of hours. I’m much more productive than with plain open gl or java3d (no more capability bits !).
I don’t like the lack of documentation about the “fuzzy features” (is shadows working ? what about sound , collisions ?) and the inexistant javadoc for methods.
I like the jogl renderer, although I’d also apreciate is there was a Direct X renderer for windows users.
I’d like to have better support for open standards like Collada model loader and also better support for HUD, particle effects, fonts and model animations.
I haven’t tried jME yet, but people here look so enthusiastic I might give it a try later…
Lilian
That’s an unbiased argument ? ;D
It’s a great one if you prefer using LWJGL 8)
Cas
you can use lwjgl with Xith3d, too 
Heh, true, I only just checked on the status of that the other day!
Cas
Java3D because
(a) I know it
(b) It has active Sun support
© Being a JCP standard its more likely to be supported by companies such as Apple.
(d) To my knwoeldge, of the 3 its the only one with multi-threading support.
As an aside, JME isnt a scene graph , its a game engine.
jME is a graph, plus or minus some bits that make it specialized for games.
Cas
I use Java3D bc. when I started FlyingGuns it was the only one available.
Second, FlyingGuns intended to be Sun friendly hoping for some company support (and we got it).
Third, it was a standard so that third-party tools (loaders) have been available.
Today, I prepare to be able to use other APIs as well. Xith3D might be the first candidate for its JOGL/AWT support (yet undecided). Then FG (or the resp. API in FG) might also serve as a realworld engine benchmark :).