Setting up Networked Testing
In the Play In dropdown menu in the Level Editor Toolbar or Blueprint Editor Toolbar, you can set how many client worlds to create when you begin a Play In Editor session. In addition, you can specify whether or not to
run a dedicated server.
The Number of Clients field allows you to specify the total number of players you want to test. If this is set to 1, and the Run Dedicated Server checkbox is unchecked, your Play In Editor session will allow you to test
standalone, non-networked gameplay.
The other basic networking option provided in the dropdown menu is the Run Dedicated Server checkbox. When this is checked, a "dedicated server" world is launched, although there is no display or local player for the dedicated server.
Using the dedicated server means that none of your clients will be running as a listen server. The dedicated server allows you to check for dedicated server only bugs, such as code that relies on a local player. A simple test configuration for Blueprints that have functionality that relies on servers and clients is to have Number of Players set to 1, and Run Dedicated Server set to true. There is only one window to test play in, but it has the full functionality of a client connected to a dedicated server.
After setting these options, pick your preferred Play In Editor mode to begin testing gameplay. If you have more than one client world and select the Viewport display
type for your Play In Editor session, one client world will be shown in the viewport, and all others will be shown in new windows. The example image below shows testing with 4 players and a dedicated server.
Click to see full-size image:
You can use Shift+Tab and Control+Tab to cycle the focus between your client windows.