ellisbrown · September 6, 2022 23:03 · Sep 6, 2022
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+# VNC Server
+
+***NOTE:*** I randomly chose display number `:99` for this demo. If you are working on a shared machine, you should choose a random number so that you do not conflict with other users.
+
+## Installation
+1. Install TigerVNC:
+    ```bash
+    sudo apt install tigervnc-standalone-server -y 
+    ```
+2. Start the VNC server:
+    ```bash
+    # create a virtual display (#99) for ai2thor to use
+    vncserver -localhost no -httpPort 5999 :99
+    ```
+    This will require you to set a password. The final output should be something like:
+    ```text
+    New 'MACHINE:99 (USER)' desktop at :99 on machine MACHINE
+    ```
+    Once the display is created, you AI2thor should have somthing to connect to.
+    3. Set the `DISPLAY` environment variable to the corresponding screen number `:99`. The conda environment *should* have this set by default. If not, run the following command to update the conda environment variable:
+    ```bash
+    conda activate <env_name>
+    conda env config vars set DISPLAY=:99
+    ```
+    - In any python code, you may also need to set the `DISPLAY` environment variable to the corresponding display number to get it to run correctly (e.g. `os.environ['DISPLAY'] = ':99'`).
+4. Fixing issues with the virtual screen
+    * See the status by running
+        ```bash
+        vncserver -list
+        ```
+        The following is an example of the output with a stale screen:
+        ```text
+        TigerVNC server sessions:
+
+        X DISPLAY #	PROCESS ID
+        :99		30309 (stale)
+        ```
+    * Kill the screen using the following command:
+        ```bash
+        vncserver -kill :99
+        ```
+        Now repeat step 2!
+
+
+##### VNC help:
+* You can use `vncserver -kill :99` to kill the server if you want.
+* viewing the display:
+  - there are various VNC viewers. I use the built in one on Mac. Instructions below:
+
+## Mac VNC Viewer:
+
+You need to forward the port of the VNC server (`5999` above) to your local machine over SSH, and have a stable connection open. Then you can open the viewer with:
+```bash
+open vnc://localhost:5999
+```
+
+## Headless VNC Server
+* install dummy XServer
+    ```bash
+    sudo apt install xterm xserver-xorg-video-dummy
+    ```
+* https://www.sproutworkshop.com/2021/04/how-to-create-a-virtual-headless-tigervnc-server-on-ubuntu-20-04/
+