[ODE] Encapsulating geometries with transforms

[Jeffrey Smith]

I am trying to implement an oriented bounding box tree collision type,
but am having some troubles.  Basically, what I want to do is have a
bunch of geoms (boxes), each parented by a transform that represents
their local displacement or rotations, all of which are then parented
by another transform, which represents the whole collection's global
position and rotation.  Like so:

          global_transform
        /       |          \
       /        |           \
      /         |            \
local_tx_0  local_tx_1     local_tx_n
    |           |              |
  box_0       box_1    ...   box_n



Furthermore, I don't want to do any collision detection between the
leaf node boxes (obviously).

I thought I could do this using the "composite geom technique",
loosely described in the users manual.  However, this won't work.  It
seems that dCollide only looks at the top node of this "tree" I have
built and kind of freaks out.  

Has anyone else done something like this?  If so, how? I can post my
code if you're curious, but it's a pretty straightforward adaptation
of what's in test_boxstack.

-jeff