---------------------------------------------------------------------------
   Update the 3D drawing data structure. This routine assumes that
   the bodies in g are in the same order as the states in x. This is
   guaranteed if TreeBldCAD is used to create the bodies.
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   Form:
   g = TreeDraw( g, x, treeDS )
---------------------------------------------------------------------------

   ------
   Inputs
   ------
   g            (1,:) CAD data structure
   x            (:,:) States
   treeDS       (:)   Tree data structure

   -------
   Outputs
   -------
   g            (1,:) CAD data structure

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