I recently borrowed some PickMouseBehavior code from Palmer's book, which seems to work pretty well.
My simple test scene graph consists of a BranchGroup containing three TransformGroups. Each TransformGroup contains one Shape3D object.  The scene graph diagram is:
      (BG)
   / ...

I've already posted this thread in comp.lang.java.programmer because I
didn't know there's a 3d-related group. Anyway, I got no answer. Hope
some of the posters here can help .. I've been trying for hours now and
still can't find a solution.

Recently I was required to write point-based rendering system with Java. I
found that the OpenGL for Java is not so good as that for c/c++. Could
someone, esp those who are experienced in such field, recommend a good Java
3D API ?  Thanks a lot