vrpn/what(): Unknown motion capture type !

[wangmenghetrue]

Hello!The motion capture system I use is another type, but it requires vrpn.WhenI use the vrpn of the motion capture system to communicate with crazyswarm.`roslaunch crazyswarm hover_swarm.launch`It will appear `what( ): Unknown motion capture type !`

Ubuntu version is ubuntu 20.04.
My local hover_swarm.launch file is follow:
# tracking
motion_capture_type: "vrpn" # one of none,vicon,optitrack,qualisys,vrpn
object_tracking_type: "motionCapture" # one of motionCapture,libobjecttracker
send_position_only: False # set to False to send position+orientation; set to True to send position only
#vicon_host_name: "vicon"
# optitrack_host_name: "optitrack"
# qualisys_host_name: "10.0.5.219"
# qualisys_base_port: 22222
vrpn_host_name: "192.168.2.137"
save_point_clouds: ~/pointCloud.ot
print_latency: False
write_csvs: False
force_no_cache: False
I also try to run mocap_helper.launch,but its result is still what( ): Unknown motion capture type !
I don't known what i should do.I really hope to get your help! Thank you very much!

[whoenig]

Are you using the latest version of the Crazyswarm (specify the commit and make sure you updated all submodules, including git submodule sync)? We had VRPN disabled for a while, but it is enabled again by default, see https://github.com/IMRCLab/libmotioncapture/blob/651bbc22c95e282d962ed39e52f0988b65ac7892/CMakeLists.txt#L9.

[wangmenghetrue]

Thank you so much for replying to me! I found that my crazyswarm is not the latest version. I reinstalled the latest version of crazyswarm as you suggested. But its hover_swarm.launch hasn'tvrpn_host_name:"".I don't know how to set IP.

When I run hover_swarm.launch, it shows
[ INFO] [1634562839.970200116]: libmotioncapture connecting to vrpn at hostname ' ' - might block indefinitely if unreachable!
vrpn_connect_udp_port: error finding host by name ().
vrpn_connection_IP: Can't set up socket to lob UDP packets!

I think the reason may be that vrpn_host_name: " " is not set in hover_swarm.launch.But its hover_swarm.launch hasn'tvrpn_host_name:"".What should i do?

[whoenig]

The setting is motion_capture_host_name, as listed in the documentation and the launch file.

[wangmenghetrue]

But our motion capture system is not vicon,optitrack,qualisys.It only uses vrpn.The same is also set motion_capture_host_name?

[whoenig]

Yes, the configuration naming is now unified.

[wangmenghetrue]

OK! Thank you very much!!