A few rviz questions:

I'm wondering if there is a hack that would enable one to draw
HUD-like items over the rviz 3D display. The most simple case would be
simply text but 2-d vector graphics (or even bitmaps) would be useful
too.

Also, is there some way to define a View that is not static relative
to the world, i.e. one that is attached to a particular frame in the
transform tree?

Finally, can anyone suggest a method for converting meshes created in
(or imported into) Blender3D, to ones that can be used in rviz?

Thanks!
Pat