simExtURDF: error: there is no joint with name ''

[eslamsherif5]

Hello, I just started learning CoppeliaSim and I'm trying to import a URDF file that includes my robot into CoppeliaSim using the Plugins > URDF Import... command But I always get an error --> there is no joint with name ' '

What I did:

1. Built the ROS package that contains the urdf file using $ catkin_make and sourced it
2. In another terminal I started $ roscore
3. In the first terminal, I ran $ ./coppeliaSim.sh

I got the following output:

[CoppeliaSimClient]    loading the CoppeliaSim library...
[CoppeliaSimClient]    done.
[CoppeliaSimClient:loadinfo]   launching CoppeliaSim...
[CoppeliaSim:loadinfo]   CoppeliaSim V4.2.0., (rev. 1), flavor: 1
[CoppeliaSim:loadinfo]   Legacy machine ID: 5000-B6EB-FFC4-9C4A-F7E3-D41D
[CoppeliaSim:loadinfo]   Machine ID: 15D3-736C-D53E-0000-00D1-0101
[CoppeliaSim:loadinfo]   using the default Lua library.
[CoppeliaSim:loadinfo]   loaded the video compression library.
[CoppeliaSim:loadinfo]   if CoppeliaSim crashes now, try to install libgl1-mesa-dev on your system:
        >sudo apt install libgl1-mesa-dev
[CoppeliaSim:loadinfo]   OpenGL: NVIDIA Corporation, Renderer: GeForce GTX 1050/PCIe/SSE2, Version: 4.6.0 NVIDIA 450.102.04
[CoppeliaSim:loadinfo]   simulator launched.
[CoppeliaSim:loadinfo]   plugin 'Assimp': loading...
[CoppeliaSim:loadinfo]   plugin 'Assimp': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'B0': loading...
[CoppeliaSim:loadinfo]   plugin 'B0': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'BWF': loading...
[CoppeliaSim:loadinfo]   plugin 'BWF': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'BubbleRob': loading...
[CoppeliaSim:loadinfo]   plugin 'BubbleRob': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'Bullet-2-78': loading...
[CoppeliaSim:loadinfo]   plugin 'Bullet-2-78': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'Bullet-2-83': loading...
[CoppeliaSim:loadinfo]   plugin 'Bullet-2-83': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'CodeEditor': loading...
[simExtCodeEditor:loadinfo]   CodeEditor plugin initialized
[CoppeliaSim:loadinfo]   plugin 'CodeEditor': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'ConvexDecompose': loading...
[CoppeliaSim:loadinfo]   plugin 'ConvexDecompose': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'ExternalRenderer': loading...
[CoppeliaSim:loadinfo]   plugin 'ExternalRenderer': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'GLTF': loading...
[CoppeliaSim:loadinfo]   plugin 'GLTF': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'Geom': loading...
[CoppeliaSim:loadinfo]   plugin 'Geom': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'ICP': loading...
[CoppeliaSim:loadinfo]   plugin 'ICP': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'IK': loading...
[CoppeliaSim:loadinfo]   plugin 'IK': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'IM': loading...
[CoppeliaSim:loadinfo]   plugin 'IM': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'K3': loading...
[CoppeliaSim:loadinfo]   plugin 'K3': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'LuaCmd': loading...
[CoppeliaSim:loadinfo]   plugin 'LuaCmd': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'LuaRemoteApiClient': loading...
[CoppeliaSim:loadinfo]   plugin 'LuaRemoteApiClient': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'MTB': loading...
[CoppeliaSim:loadinfo]   plugin 'MTB': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'Newton': loading...
[CoppeliaSim:loadinfo]   plugin 'Newton': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'ODE': loading...
[CoppeliaSim:loadinfo]   plugin 'ODE': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'OMPL': loading...
[CoppeliaSim:loadinfo]   plugin 'OMPL': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'OpenGL3Renderer': loading...
[CoppeliaSim:loadinfo]   plugin 'OpenGL3Renderer': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'OpenMesh': loading...
[CoppeliaSim:loadinfo]   plugin 'OpenMesh': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'Qhull': loading...
[CoppeliaSim:loadinfo]   plugin 'Qhull': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'RML2': loading...
[CoppeliaSim:loadinfo]   plugin 'RML2': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'ROS': loading...
[CoppeliaSim:loadinfo]   plugin 'ROS': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'RRS1': loading...
[CoppeliaSim:loadinfo]   plugin 'RRS1': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'RemoteApi': loading...
[simExtRemoteApi:loadinfo]   starting a remote API server on port 19997
[CoppeliaSim:loadinfo]   plugin 'RemoteApi': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'SDF': loading...
[CoppeliaSim:loadinfo]   plugin 'SDF': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'SurfRec': loading...
[CoppeliaSim:loadinfo]   plugin 'SurfRec': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'UI': loading...
[CoppeliaSim:loadinfo]   plugin 'UI': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'URDF': loading...
[CoppeliaSim:loadinfo]   plugin 'URDF': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'URLDrop': loading...
[CoppeliaSim:loadinfo]   plugin 'URLDrop': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'Vision': loading...
[CoppeliaSim:loadinfo]   plugin 'Vision': load succeeded.
[CoppeliaSim:loadinfo]   plugin 'ZMQ': loading...
[CoppeliaSim:loadinfo]   plugin 'ZMQ': load succeeded.
[CoppeliaSim:loadinfo]   using the 'Geometric' plugin.
[CoppeliaSim:loadinfo]   using the 'IK' plugin.
[simExtURDF:error]   simExtURDF: error: there is no joint with name ''
[simExtURDF:error]   simExtURDF: error: there is no joint with name ''
[simExtURDF:error]   simExtURDF: error: there is no joint with name ''
[simExtURDF:error]   simExtURDF: error: there is no joint with name ''
QH6214 qhull input error: not enough points(3) to construct initial simplex (need 4)

While executing:  | qhull 
Options selected for Qhull 2012.1 2012/02/18:
  run-id 930089492  _pre-merge  _zero-centrum
[simExtURDF:error]   simExtURDF: error: there is no joint with name ''
qhull precision warning: 
The initial hull is narrow (cosine of min. angle is 0.9999999999999993).
Is the input lower dimensional (e.g., on a plane in 3-d)?  Qhull may
produce a wide facet.  Options 'QbB' (scale to unit box) or 'Qbb' (scale
last coordinate) may remove this warning.  Use 'Pp' to skip this warning.
See 'Limitations' in qh-impre.htm.

I attached a picture of the robot after importing it into CoppeliaSim

Thanks.

[Coppelia]

Hello, can you make sure that the mentioned joints actually have a name in the URDF file? If not, try to give them an appropriate name

[sadiq26]

I got the same error when using it on windows

[Coppelia]

Please use the last source code. Those messages were erroneously output, and we have fixed that. Or you can simply ignore those messages