Running vedo on a Server

[SiriusFuenmayor]

Hello, I have succesfully build a FEniCS Docker container incluiding vedo, but when I try to use vedo I encounter the error:

ERROR: In /work/standalone-x64-build/VTK-source/Rendering/OpenGL2/vtkXOpenGLRenderWindow.cxx, line 1223 vtkXOpenGLRenderWindow (0x24992f0): bad X server connection. DISPLAY=Aborted (core dumped)

It appears that vedo or vtk can not run without the X server. Is there any way to solve this issue?

[RubendeBruin]

I'm reporting what worked for me on ubuntu 18.04 server.

1. Install libgl1-mesa and xvfb:

 sudo apt-get install libgl1-mesa-dev libgl1-mesa-glx  xvfb

2. Execute on startup:

#!/bin/bash
# 
set -x
export DISPLAY=:99.0
Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &
sleep 3
set +x
exec "$@"

save the bash script above as /etc/rc.local (or any other file to be called) and use chmod +x to make it executable.

3. Run a python script test:

plt = vedo.Plotter(offscreen=True)
plt += vedo.Cube()
plt.show()
plt.screenshot(filename)
plt.close()

[XushanLu]

Hi,

I tried this on my Ubuntu 22.04 LTS system connected via SSH. Both the test suggested here and my own script failed with the following error:
[1] 6992 abort (core dumped)

I believe I have installed all the libraries mentioned and set up the rc.local file both in /etc/ and in the folder that I am working in.

Is anyone experiencing such an error?

Thanks.

[marcomusy]

Have you tried running manually the bash script (point 2.) in the server?
to make sure the xvfb gets started.

[XushanLu]

Hi Marco,

Thanks very much for your quick reply. I tried that manually and I find my zsh complaining. Then I switched to bash and it seems to be working under bash. I don't know full well what might be the issue behind the failure of zsh. I will simply switch to bash to get things done.

[fstrazzante]

Hello,
thank you Marco for the module is amazing!
I still have this problem on Ubuntu server 20.04.
When I try to execute

import vedo
plt = vedo.Plotter(offscreen=True)
plt += vedo.Cube()
plt.show()
plt.screenshot("a.png")
plt.close()

I get:

Aborted

I installed all the packages suggested by RubendeBruin's answer and executed the bash script. For the bash script I executed on the server which bash and got /usr/bin/bash so, this is the bash script:

#!/usr/bin/bash

set -x
export DISPLAY=:99.0
Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &
#sleep 3
set +x
exec "$@"
echo Just a regular string

I did chmod u+x set_xvfb.sh, executed with ./set_xvfb.sh and got this output:

+ export DISPLAY=:99.0
+ DISPLAY=:99.0
+ set +x
Just a regular string
+ Xvfb :99 -screen 0 1024x768x24

And then, executing the python script, I still have:
Aborted

(Context)
vedo --info

vedo version      : 2022.4.2   https://vedo.embl.es
vtk version       : 9.2.5
numpy version     : 1.23.1
python version    : 3.8.10 (default, Nov 14 2022, 12:59:47) [GCC 9.4.0]
python interpreter: /usr/bin/python3
vedo installation : /home/flogicalg/.local/lib/python3.8/site-packages/vedo
system            : Linux 5.4.0-105-generic posix x86_64
monitor           : info is unavailable. Try "pip install screeninfo".

Python: 3.8.10
Ubuntu: Ubuntu 20.04.5 LTS

Anyone know how to resolve this?

[marcomusy]

Hi Francesco,
are you also getting the same problem if you run this script?

#!/usr/bin/env python
#
import vtk
import time

cone = vtk.vtkConeSource()

mapper = vtk.vtkPolyDataMapper()
mapper.SetInputConnection(cone.GetOutputPort())

actor = vtk.vtkActor()
actor.SetMapper(mapper)

ren = vtk.vtkRenderer()
ren.AddActor(actor)

renWin = vtk.vtkRenderWindow()
renWin.SetSize(500, 500)
renWin.AddRenderer(ren)

# iren = vtk.vtkRenderWindowInteractor()
# iren.SetRenderWindow(renWin)

renWin.SetOffScreenRendering(1)
renWin.Render()

[fstrazzante]

Hi Marco,
thank you, I tried to execute the script you shared and I got this error:

 2023-02-02 08:33:45.587 (   2.324s) [        ACC37740]vtkXOpenGLRenderWindow.:464    ERR| vtkXOpenGLRenderWindow (0x25dfd00): bad X server connection. DISPLAY=
Aborted

[marcomusy]

uhm i was suspecting that... it looks like your system has some problem with running Xvfb, unfortunately I would not know how to fix that as I'm not very familiar with it... but for sure it's not related to vedo per se. :(