RuntimeError: Aspect_DisplayConnectionDefinitionErrorCan not connect to the server "" raised from method Display3d of class Display3d

[Lydiagugugaga]

Dear community,
My problem is "can't use the class Viewer3d() from OCC.Display.OCCViewer import Viewer3d

viewer = Viewer3d() <-- Display3d.__init__(self) <-- _Visualization.Display3d_swiginit(self, _Visualization.new_Display3d())
RuntimeError: Aspect_DisplayConnectionDefinitionErrorCan not connect to the server "" raised from method Display3d of class Display3d

The version is pythonocc-core=7.7.2

I can do it in windows, but it can't work in linux. viewer = Viewer3d()
How to solve this problem for using in linux?
I wish for your help.

[vinnyvimto]

So running the offscreen rendering example, which uses the Viewer3d, I have it working fine. This was with

• ubuntu 23.10
• python 3.10
• pythonocc-core 7.7.2

Annoyingly though when I try to run this in a ubuntu:23.10 docker container with the exact same dependencies I get the above error. Would love to know a way around it so I can run workloads with it in docker.

Edit: I did actually get this working following this advice: #708 (comment)

The important part was installing xvfb

apt-get install xvfb
export DISPLAY=:99
Xvfb :99 -screen 0 640x480x24 &

The X virtual framebuffer (Xvfb) is an X server that can run on machines with no display hardware and no physical input devices. It emulates a dumb framebuffer using virtual memory.

[tpaviot]

On Linux, to instanciate the Viewer3d class, you need to have a x server installed, or an x server emulator (like xvfb)