Hello, I am trying to connect between ROS and Motive(optitrack) using VRPN but I got stuck. I am wondering if you can help me to solve the error. I am using ROS kinetic with Ubuntu 16.4. I followed the steps needed to connect using vrpn and run the roslaunch vrpnclientros sample.launch server:=239.255.42.99 and it said connection established. But when I run rostopic echo /Tracker/pose it gave me an error saying the "topic doesn't appear to be published yet".

Thanks,

---

Edit: @paulbovbel To give you more info on this. This is what I am getting right now:

ubuntuxenial@ubuntuxenial-VirtualBox:~$ roslaunch vrpn_client_ros sample.launch server:=192.168.56.1
... logging to /home/ubuntuxenial/.ros/log/ffb55d00-6724-11e7-b1f2-0800279f7859/roslaunch-ubuntuxenial-VirtualBox-18941.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://ubuntuxenial-VirtualBox:39717/

SUMMARY
========

PARAMETERS
 * /rosdistro: kinetic
 * /rosversion: 1.12.7
 * /vrpn_client_node/broadcast_tf: True
 * /vrpn_client_node/frame_id: world
 * /vrpn_client_node/port: 3883
 * /vrpn_client_node/refresh_tracker_frequency: 1.0
 * /vrpn_client_node/server: 192.168.56.1
 * /vrpn_client_node/update_frequency: 100.0
 * /vrpn_client_node/use_server_time: False

NODES
  /
    vrpn_client_node (vrpn_client_ros/vrpn_client_node)

auto-starting new master
process[master]: started with pid [18952]
ROS_MASTER_URI=http://localhost:11311

setting /run_id to ffb55d00-6724-11e7-b1f2-0800279f7859
process[rosout-1]: started with pid [18965]
started core service [/rosout]
process[vrpn_client_node-2]: started with pid [18968]
[ INFO] [1499879429.043896446]: Connecting to VRPN server at 192.168.56.1:3883
[ INFO] [1499879430.048286417]: Connection established

And I tried to run rostopic list on another terminal and got the following:

ubuntuxenial@ubuntuxenial-VirtualBox:~$ rostopic list
/rosout
/rosout_agg

So here you can see rigid body isnt published. I am guessing there might be a problem in my Ip address. I am using Ubuntu on virtual box. How should you think I have to create a network between the Ubuntu's virtual box and the host computer where Optitrack is operating?