Check for OpenGL before running meshviewer

[excalamus]

Previously, the command would dispatch regardless of the OpenGL status. In cases where OpenGL was unavailable, the process would continue, start the client, and then run into an OpenGL error. End-users would sometimes not be informed of errors.

This change checks for OpenGL prior to dispatch, alerting the user of any errors.

[excalamus]

I noticed there exist several issues related to end-users running meshviewer viewer and not seeing the window. Issues include: #63, #57, #44, #78, and #75.

[AntiLibrary5]

I noticed there exist several issues related to end-users running meshviewer viewer and not seeing the window. Issues include: #63, #57, #44, #78, and #75.

Your insight here made it work for me.
#63 (comment)

There are a bunch of things you need to get right. But having the nvidia drivers is one of them. Finally using a nvidia/cudagl base image (instead of a base python image) made it work for me.

For ref for others (assuming psbody mesh repo in pwd):

FROM nvidia/cudagl:11.4.0-runtime-ubuntu20.04

# Set environment variables
ENV DEBIAN_FRONTEND=noninteractive
ENV __GLVND_DISALLOW_PATCHING 1
# Env vars for the nvidia-container-runtime.
ENV NVIDIA_VISIBLE_DEVICES all
ENV NVIDIA_DRIVER_CAPABILITIES graphics,utility,compute

# Set the working directory
WORKDIR /home

# Install any python packages you need
COPY . .

RUN apt-get update -q && apt-get install -y -qq x11-apps python3-pip python3-dev python3-opencv freeglut3-dev

RUN pip install --upgrade pip && \
	pip install --no-cache-dir -r requirements.txt && \
	pip install PyOpenGL==3.1.1a1 && \
	cd ./mesh && \
	make all && \
	cd .. && \

Build the image as follows:

docker run -it -e DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix --name <NAME> <IMAGE> bash

In the container try running:

xclock

meshviewer open

Hope it helps.
Best.