If you want to use a map that isn't one of the normal maps for the game, you will need to download it from the workshop. Thankfully, Garry's Mod not only offers a way to launch workshop maps, but even ways to allow to load multiple at once, allowing you to change between them using the in-game voting system or even the changelevel command.
FINDING A COLLECTION ID
- Browse the steam workshop and find a Collection you would like to use. You can find the Steam Workshop for Garry's Mod at: https://steamcommunity.com/app/4000/workshop/.
- Once you have found the collection you wish to use, you can find the Workshop ID in the URL of the web page for the map.
- Copy the numbers at the end of the URL - this Workshop ID that you will need to paste into your server config later.
Example URL:https://steamcommunity.com/sharedfiles/filedetails/?id=123456789
In the example above, the Workshop ID would be 123456789.
LOADING A COLLECTION ONTO YOUR SERVER
If you just want to load a specific workshop map when you start your server, then you can do so via your properties file.
- Login to your Control Panel.
- Click on the Files > Config Files tab on the left.
- Open the Garry's Mod Server Settings config file.
- Adjust the
host_workshop_collectionvalue to the ID of the Workshop collection you wish to use.
- Press Save at the bottom of the page and restart your server.
