On Tue, Apr 5, 2011 at 5:05 PM, Dejan Pangercic wrote: > Hi Sabrina, > >> you should instantiate the TransformListener outside the callback: >> >> tf::TransformListener *tf_listener; > this is very interesting. But do you know why would it be necessary to > have it outside the callback? Is there a documentation about this? I believe the destructor for the listener will shut down the connection. Many ROS interfaces use the RAII approach. --  joq