SharedGroup Example Code

   TransformGroup groupA = new TransformGroup( );
   TransformGroup groupB = new TransformGroup( );
   Shape3D shape1 = new Shape3D( geom1, app1 );
   Shape3D shape2 = new Shape3D( geom2, app1 );
   . . .
   SharedGroup shared = new SharedGroup( );
   shared.addChild( shape1 );
   shared.addChild( shape2 );
   shared.compile( );
   . . .
   Link linkA = new Link( shared );
   Link linkB = new Link( shared );
   . . .
   groupA.addChild( linkA );
   groupB.addChild( linkB );