Thanks again for your answers, but there are still some things I do not get. > > > On Tue, Dec 21, 2010 at 5:55 PM, Josh Faust wrote: >>> I use ros::init() to specify the node namespace. >> ros::init() specifies the node's name, not its namespace.  The node's name >> determines where a private name ("~name") goes. > My bad then, I missunderstood the node name with its namespace. The only way to add a namespace to the node is through a node handle then? > Plus, it's better not to use the node name when advertising topics to other nodes. In complex roslaunch scenarios, node names are likely to be changed in the launch file. So, other nodes should rely on > well-known topic names, not on guessing the node name. > > Several alternate implementations may advertise the same topic. For example, many camera drivers advertise "camera/image_raw" and > "camera/camera_info". If there is more than one camera, each will be pushed down into its own namespace: "front/camera/image_raw", etc. Consumers of the images need not worry about which device driver sends them. That was exactly the problem I found, many instances from a same node may be executed at the same time trying to advertise the same topic. That is the main reason I wanted to use namespaces. I do not think I understood the camera example. When you say topics will be pushed down, you mean if the developer explicity uses the node namespace? I can not see either, how consumers connected to the previously named topic "camera/image_raw" can resolve the topic name if there is no additional information (like I wanted to connect to the front camera instead of the back one). I hope I expressed myself correctly. > -- >  joq > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > > > ______________________________________ > View message @ > http://ros-users.122217.n3.nabble.com/Node-Handle-details-tp2126850p2129313.html > > To unsubscribe from Node Handle details, visit > http://ros-users.122217.n3.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=2126850&code=am5wZXJlekBpcmkudXBjLmVkdXwyMTI2ODUwfDE4ODQ4Nzc2NDQ= -- View this message in context: http://ros-users.122217.n3.nabble.com/Node-Handle-details-tp2126850p2134341.html Sent from the ROS-Users mailing list archive at Nabble.com.