I’m working with OpenAI Gym environments in Google Colab but I’m having trouble getting the visual output to show up. Since Colab runs everything on their remote servers, the standard rendering methods don’t work like they would locally.
I’ve seen some fixes that work for regular Jupyter notebooks, but those don’t seem to help with Colab since I can’t access the actual server where my code is running.
Does anyone know of a way to get gym environment visualization working properly in Google Colab? Any suggestions would be really helpful.
I’ve had good luck using the pyglet backend with a virtual display. Install pyglet and xvfb via apt-get, then set your DISPLAY environment variable before importing gym. You get way more control over rendering than just switching modes. Works great for environments with complex visuals or when you need consistent frame timing. Just make sure you configure the virtual display before creating your environment - otherwise you’ll hit the same headless server errors.
switch to rgb_array mode instead of human mode when u call render(). then just display the frames with matplotlib or convert them to video. works great for most environments in colab.
Had this same issue last month. Use pyvirtualdisplay with xvfb - it’s rock solid for gym visualization in Colab. Just pip install pyvirtualdisplay, import Display, and start the virtual display before you initialize your environment. Then render and capture frames like normal. Colab needs that virtual display buffer since there’s no actual screen on the remote server. Works great across all the gym environments I’ve tested.
you can try using gym.wrappers.Monitor to save videos that play inline in colab. that worked for me when i had the same issue. just remember to handle it differently than in your normal jupyter setup.
you could also use OpenCV to capture and display frames directly. just use cv2_imshow() instead of regular imshow in colab - it handles the backend automatically. way easier than dealing with virtual displays.