Render SMPL Meshes with HeadlessRenderer

[LeoHsuProgrammingLab]

Hi, thank you for the amazing work!

May I ask if there is any method to render the SMPL meshes without using the display?
I got the following error:

ERROR - visualize_poses - Failed to initialize HeadlessRenderer: (standalone) cannot create context

Sincerely,
Leo

[anewell]

Hi Leo,

Headless rendering should be supported. Perhaps some of the info in the readme about setting up a display in a remote context might help? Otherwise the issue could be specific to aitviewer, it is difficult to say exactly the source of your error without more info. Generally, if you can set up aitviewer to perform headless rendering then this repo's rendering code should work okay.

Hope that helps!
Alejandro

[sunshineinsandiego]

I am actually having the same problem. I'm running comotion in a docker container and end up with a .pt / .txt output, but no video rendering. The error I receive is:

2025-09-01 01:09:10 - INFO - get_window_cls - Attempting to load window class: moderngl_window.context.headless.Window
Traceback (most recent call last):
  File "/opt/ml_comotion/demo.py", line 350, in <module>
    main()
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1442, in __call__
    return self.main(*args, **kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1363, in main
    rv = self.invoke(ctx)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1226, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 794, in invoke
    return callback(*args, **kwargs)
  File "/opt/ml_comotion/demo.py", line 344, in main
    visualize_poses(
  File "/opt/ml_comotion/demo.py", line 145, in visualize_poses
    viewer = HeadlessRenderer(size=(image_width, image_height))
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/aitviewer/headless.py", line 21, in __init__
    super().__init__(**kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/aitviewer/viewer.py", line 127, in __init__
    self.window = base_window_cls(
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl_window/context/headless/window.py", line 27, in __init__
    self.init_mgl_context()
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl_window/context/headless/window.py", line 45, in init_mgl_context
    self._ctx = moderngl.create_standalone_context(
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl/__init__.py", line 2304, in create_standalone_context
    return create_context(standalone=True, **kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl/__init__.py", line 2254, in create_context
    ctx.mglo, ctx.version_code = mgl.create_context(glversion=require, mode=mode, **settings)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/glcontext/__init__.py", line 90, in create
    return x11.create_context(**kwargs)
Exception: (standalone) XOpenDisplay: cannot open display

This is after following the instructions on the readme:

$ Xvfb :0 -screen 0 640x480x24
$ export DISPLAY=:0.0
$ python demo.py -i /workspace/datasets/video01.mp4 -o /workspace/outputs/video01/

Any suggestions would be appreciated, thanks!

[sunshineinsandiego]

Have also tried all of the following without success:

# xvfb-run -a -s "-screen 0 640x480x24" \
  env GLCONTEXT_BACKEND=osmesa python /opt/ml_comotion/demo.py \
    -i video.mp4
    -o results/
Running CoMotion: 0it [00:00, ?it/s]2025-09-01 14:39:50 - INFO - yield_image_from_video - Yielding 1000000000 frames 
2025-09-01 14:39:50 - INFO - yield_image_from_video - Starting from frame 0
Running CoMotion: 1752it [04:00,  7.28it/s]
2025-09-01 14:44:04 - INFO - visualize_poses - Rendering SMPL video: 
2025-09-01 14:44:04 - INFO - yield_image_from_video - Yielding 1000000000 frames
2025-09-01 14:44:04 - INFO - yield_image_from_video - Starting from frame 0
2025-09-01 14:44:16 - INFO - get_window_cls - Attempting to load window class: moderngl_window.context.headless.Window
Traceback (most recent call last):
  File "/opt/ml_comotion/demo.py", line 350, in <module>
    main()
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1442, in __call__
    return self.main(*args, **kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1363, in main
    rv = self.invoke(ctx)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1226, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 794, in invoke
    return callback(*args, **kwargs)
  File "/opt/ml_comotion/demo.py", line 344, in main
    visualize_poses(
  File "/opt/ml_comotion/demo.py", line 145, in visualize_poses
    viewer = HeadlessRenderer(size=(image_width, image_height))
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/aitviewer/headless.py", line 21, in __init__
    super().__init__(**kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/aitviewer/viewer.py", line 127, in __init__
    self.window = base_window_cls(
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl_window/context/headless/window.py", line 27, in __init__
    self.init_mgl_context()
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl_window/context/headless/window.py", line 45, in init_mgl_context
    self._ctx = moderngl.create_standalone_context(
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl/__init__.py", line 2304, in create_standalone_context
    return create_context(standalone=True, **kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl/__init__.py", line 2254, in create_context
    ctx.mglo, ctx.version_code = mgl.create_context(glversion=require, mode=mode, **settings)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/glcontext/__init__.py", line 90, in create
    return x11.create_context(**kwargs)
Exception: (standalone) glXChooseFBConfig failed

# xvfb-run -a -s "-screen 0 640x480x24" env GLCONTEXT_BACKEND=egl python /opt/ml_comotion/demo.py   -i video01.mp4   -o video01/
Running CoMotion: 0it [00:00, ?it/s]2025-09-01 14:34:44 - INFO - yield_image_from_video - Yielding 1000000000 frames 
2025-09-01 14:34:44 - INFO - yield_image_from_video - Starting from frame 0
Running CoMotion: 1752it [04:00,  7.28it/s]
2025-09-01 14:38:58 - INFO - visualize_poses - Rendering SMPL video:
2025-09-01 14:38:58 - INFO - yield_image_from_video - Yielding 1000000000 frames from 
2025-09-01 14:38:58 - INFO - yield_image_from_video - Starting from frame 0
2025-09-01 14:39:09 - INFO - get_window_cls - Attempting to load window class: moderngl_window.context.headless.Window
Traceback (most recent call last):
  File "/opt/ml_comotion/demo.py", line 350, in <module>
    main()
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1442, in __call__
    return self.main(*args, **kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1363, in main
    rv = self.invoke(ctx)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1226, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 794, in invoke
    return callback(*args, **kwargs)
  File "/opt/ml_comotion/demo.py", line 344, in main
    visualize_poses(
  File "/opt/ml_comotion/demo.py", line 145, in visualize_poses
    viewer = HeadlessRenderer(size=(image_width, image_height))
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/aitviewer/headless.py", line 21, in __init__
    super().__init__(**kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/aitviewer/viewer.py", line 127, in __init__
    self.window = base_window_cls(
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl_window/context/headless/window.py", line 27, in __init__
    self.init_mgl_context()
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl_window/context/headless/window.py", line 45, in init_mgl_context
    self._ctx = moderngl.create_standalone_context(
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl/__init__.py", line 2304, in create_standalone_context
    return create_context(standalone=True, **kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl/__init__.py", line 2254, in create_context
    ctx.mglo, ctx.version_code = mgl.create_context(glversion=require, mode=mode, **settings)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/glcontext/__init__.py", line 90, in create
    return x11.create_context(**kwargs)
Exception: (standalone) glXChooseFBConfig failed

[y25789158-max]

Have also tried all of the following without success:

# xvfb-run -a -s "-screen 0 640x480x24" \
  env GLCONTEXT_BACKEND=osmesa python /opt/ml_comotion/demo.py \
    -i video.mp4
    -o results/
Running CoMotion: 0it [00:00, ?it/s]2025-09-01 14:39:50 - INFO - yield_image_from_video - Yielding 1000000000 frames 
2025-09-01 14:39:50 - INFO - yield_image_from_video - Starting from frame 0
Running CoMotion: 1752it [04:00,  7.28it/s]
2025-09-01 14:44:04 - INFO - visualize_poses - Rendering SMPL video: 
2025-09-01 14:44:04 - INFO - yield_image_from_video - Yielding 1000000000 frames
2025-09-01 14:44:04 - INFO - yield_image_from_video - Starting from frame 0
2025-09-01 14:44:16 - INFO - get_window_cls - Attempting to load window class: moderngl_window.context.headless.Window
Traceback (most recent call last):
  File "/opt/ml_comotion/demo.py", line 350, in <module>
    main()
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1442, in __call__
    return self.main(*args, **kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1363, in main
    rv = self.invoke(ctx)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1226, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 794, in invoke
    return callback(*args, **kwargs)
  File "/opt/ml_comotion/demo.py", line 344, in main
    visualize_poses(
  File "/opt/ml_comotion/demo.py", line 145, in visualize_poses
    viewer = HeadlessRenderer(size=(image_width, image_height))
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/aitviewer/headless.py", line 21, in __init__
    super().__init__(**kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/aitviewer/viewer.py", line 127, in __init__
    self.window = base_window_cls(
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl_window/context/headless/window.py", line 27, in __init__
    self.init_mgl_context()
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl_window/context/headless/window.py", line 45, in init_mgl_context
    self._ctx = moderngl.create_standalone_context(
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl/__init__.py", line 2304, in create_standalone_context
    return create_context(standalone=True, **kwargs)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl/__init__.py", line 2254, in create_context
    ctx.mglo, ctx.version_code = mgl.create_context(glversion=require, mode=mode, **settings)
  File "/opt/conda/envs/comotion/lib/python3.10/site-packages/glcontext/__init__.py", line 90, in create
    return x11.create_context(**kwargs)
Exception: (standalone) glXChooseFBConfig failed

# xvfb-run -a -s "-screen 0 640x480x24" env GLCONTEXT_BACKEND=egl python /opt/ml_comotion/demo.py   -i video01.mp4   -o video01/
Running CoMotion: 0it [00:00, ?it/s]2025-09-01 14:34:44 - INFO - yield_image_from_video - Yielding 1000000000 frames 
2025-09-01 14:34:44 - INFO - yield_image_from_video - Starting from frame 0
Running CoMotion: 1752it [04:00,  7.28it/s]
2025-09-01 14:38:58 - INFO - visualize_poses - Rendering SMPL video:
2025-09-01 14:38:58 - INFO - yield_image_from_video - Yielding 1000000000 frames from 
2025-09-01 14:38:58 - INFO - yield_image_from_video - Starting from frame 0
2025-09-01 14:39:09 - INFO - get_window_cls - Attempting to load window class: moderngl_window.context.headless.Window
Traceback (most recent call last):
 File "/opt/ml_comotion/demo.py", line 350, in <module>
   main()
 File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1442, in __call__
   return self.main(*args, **kwargs)
 File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1363, in main
   rv = self.invoke(ctx)
 File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 1226, in invoke
   return ctx.invoke(self.callback, **ctx.params)
 File "/opt/conda/envs/comotion/lib/python3.10/site-packages/click/core.py", line 794, in invoke
   return callback(*args, **kwargs)
 File "/opt/ml_comotion/demo.py", line 344, in main
   visualize_poses(
 File "/opt/ml_comotion/demo.py", line 145, in visualize_poses
   viewer = HeadlessRenderer(size=(image_width, image_height))
 File "/opt/conda/envs/comotion/lib/python3.10/site-packages/aitviewer/headless.py", line 21, in __init__
   super().__init__(**kwargs)
 File "/opt/conda/envs/comotion/lib/python3.10/site-packages/aitviewer/viewer.py", line 127, in __init__
   self.window = base_window_cls(
 File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl_window/context/headless/window.py", line 27, in __init__
   self.init_mgl_context()
 File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl_window/context/headless/window.py", line 45, in init_mgl_context
   self._ctx = moderngl.create_standalone_context(
 File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl/__init__.py", line 2304, in create_standalone_context
   return create_context(standalone=True, **kwargs)
 File "/opt/conda/envs/comotion/lib/python3.10/site-packages/moderngl/__init__.py", line 2254, in create_context
   ctx.mglo, ctx.version_code = mgl.create_context(glversion=require, mode=mode, **settings)
 File "/opt/conda/envs/comotion/lib/python3.10/site-packages/glcontext/__init__.py", line 90, in create
   return x11.create_context(**kwargs)
Exception: (standalone) glXChooseFBConfig failed

Hi, may I ask if you’ve managed to resolve this issue? If so, could you share what worked for you? Thanks!