Hi @seong_drgn
The problem comes from vec_task.py line 89
The configuration for enabling camera sensors (enableCameraSensors) in Isaac Gym environments is defined at task.env.enableCameraSensors however, the configuration in the script is looking at task.enableCameraSensors.
Because this last sub-key does not exist, enable_camera_sensors = config.get("enableCameraSensors", False) is always returning False. Then, when headless is True, the final graphics_device_id is -1
To create and set the sub-key, when running the script, use +task.enableCameraSensors=True
Example:
python train.py task=Cartpole headless=True +task.enableCameraSensors=True
Or edit the vec_task.py line 89
enable_camera_sensors = config["env"].get("enableCameraSensors", False)
and use the original configuration sub-key:
Example:
python train.py task=Cartpole headless=True task.env.enableCameraSensors=True