Prerequisites

Before starting this guide you will need a working multiplayer Unreal Engine 5 project and a source build of Unreal Engine.

What is a Dedicated Server?

A dedicated server, in game development terms, is a computer that can run a standalone piece of software which only handles the game world and server code.

It does not spawn a player character and does not count as a connected player.

The first method when setting up networking in a multiplayer game for many is a listen server.

A listen server is perfect for many styles of multiplayer games as it works well with games with small player counts per server (2 to 16), keeps costs down for developers and make developing features easier with faster testing between two clients.

For some games this isn’t ideal as players might cheat, have sync inconsistencies between clients that would be game breaking (fighting games over large latency) and larger scale games causing the host machine to slow down impacting other player’s experiences.

Dedicated servers are perfect to remedy these issues. Running the files that we will be creating on its own machine, with ports setup correctly, will only process your game world and keep an server of your game running 24/7.

Automatic Session

We need our server to automatically create a session and then load the map on launch.

In our example project, which can be downloaded in a first person or third person format, we create our MainMenu widget and add it to the screen in our main menu level blueprint.

We need to adjust this so if it is a dedicated server then we ignore the menus entirely and create a session for our players to join!

To achieve this, we simply add a branch and an “Is Dedicated Server” node before our widget creation.

This is then connected together on the False pin as we don’t want the code to run if our platform is “Dedicated Server”.

On the True pin we then add a Create Advanced Session node with our desired settings.

If our session creation was a success we then open our level with the option ?listen so that our server can accept connections to the map.

Lastly, we compile and save our changes!

Choosing the Default Server Map

By default our dedicated server loads into an engine map called “Entry”. We need to change this to our own map to ensure that we can load players into the game.

Firstly, open the edit menu in the top left and then click Project Settings.

We then click the “Maps & Modes” section of the Project Settings.

We then click the Advanced drop down option in the “Default Maps” section.

Finally, set the “Server Default Map” option to the map that you want to start your server on. In this case we are using our “menu” map and making changes later in the guide to add dedicated server functionality.

No Default Character in the Level

As we are using a dedicated server, we no longer need a character spawned for the authority (server host).

Our level has a character blueprint inside of the level that gets controlled by the first player connected.

We need to remove this to prevent a character standing in the level with no player!

The Project Launcher

The project launcher is a built in tool of Unreal Engine that allows you to build versions of your game based on profiles that you can create.

One of the abilities of the project launcher is the dedicated server!

We can open the project launcher by opening the Tools menu at the top of the editor window and selecting the Project Launcher in the tools section of the menu.

You should now see a large empty menu! We now need to add our custom profile for our game!

We need to create our custom profile to specify to the engine that we want a dedicated server build.

Creating the Custom Profile

Firstly, click the Add button in the bottom right, then click “Create Custom Profile”.

You should now see a large menu of options appear.

In the cook section, we need to open the drop down menu and change “On the fly” to “By the book”.

We then scroll down the Cooked Platforms list and find the server platform we want to build for. For this guide we are building a dedicated server for Windows.

You can choose LinuxServer if you need an x86/64 Linux server or LinuxArm64 if you want to host your server on Linux Arm. If you do not understand this, simply choose WindowsServer.

We then scroll down further and select all of the maps that you want to include in your server. In this guide we have selected both of the maps in the Unreal Engine 5

Next in the Package section, click the drop down menu and change “Do not package” to “Package & store locally”.

This then generates you a default path inside of your project folder to build the server. This can be changed to anywhere you want using the directory picker “Browse” button.

Then, in the Deploy section, click the drop down menu and change “Copy to device” to “Do not deploy”.

Finally, we can give our new profile a name to remember what this Profile builds.

Creating the Dedicated Server

Now that we have our profile all setup, we can now build our dedicated server!

Click the back button to return to the main Project Launcher menu.

We can now see our new profile in the list of custom launch profiles.

Building the Files

To build the dedicated server using our custom profile, simply press the launch button (Controller and display icon).

You now see the process of your dedicated server automatically building!

Now wait until the process has completed. The first time you run your profile it can take a long time. Leave this to fully complete before moving onto the final step!

Testing the Dedicated Server

Now that our dedicated server has built successfully, navigate to the folder you selected earlier to see the executable.

If you left this option default in the previous step, the folder found in your project folder then Saved/StagedBuilds and then the platform name. In this case “WindowsServer“.

From here we can open our Server.exe to open the server. This will open in the background and is hard to monitor and close.

To make this easier to use, firstly create a shortcut in Windows for your server executable.

We then open the executable and add the “-log” launch option to the end of the target section. This will make the server open as a window and print any logging messages on to the screen.

Now open the shortcut to your server and text will fill the window. This is your server initializing and setting up a session for your players to join!

On the client’s view it now shows the dedicated server session!

Demonstration

With three clients open inside the editor and our dedicated server open, the clients can connect to the session and see each other move without needing a full client open to host the game!

Project Files

Conclusion

You now have a dedicated server of your game building with the ability to be connected to!

With this knowledge, you’re one step closer to launching a fully featured multiplayer game that performs well and delivers a consistent experience to players!

Further Reading

• Click here to read the Unreal Engine Dedicated Server Guide
• For more networking fundamentals click here for the UE Networking Overview
• It’s always great to read up on how to build projects based on our learning of the project launcher, Click here for the UE documentation on Building Projects

The post How to build a Dedicated Server for your Unreal Engine 5 Game appeared first on Couch Learn.

Prerequisites

This guide expects a basic level of knowledge of C++ in Unreal Engine 5.

To follow this guide you also need to have one of the following:

• Visual Studio for Windows
  or
• XCode for MacOS

These programs are used to compile the C++ code into your project. If you do not have a IDE installed, the engine will prompt you to install one.

What is a C++ Blueprint Function Library

The C++ Blueprint Library is a built in Unreal Engine class that allows code to be written using the C++ programming language to be used in both C++ code or in Blueprints!

This means we can move our slow blueprints nodes into optimised C++ code then run these functions inside of our blueprint code.

This gives us the power of C++ inside of blueprints in an easily accessible form!

How to create a C++ Blueprint Function Library

C++ Project vs Blueprint Project

Firstly, we need to find out if our project is a C++ enabled project, or only a blueprint enabled project. Luckily this is easy to do!

Click the Tools drop down at the top of the screen, then click “New C++ Class“.

If you do not have one of the preqrequisite programs installed as explained earlier, the engine will instruct you what you need to install.

In our case, for this guide, we used a MacOS machine, and so we installed XCode.

Next, the dialog box will appear asking which type of “Parent Class” you wish to use when creating your new class.

As we are making a C++ blueprint function library, we scroll down near the bottom and click “Blueprint Function Library”. To move to the next section, we press the blue NEXT button.

We then are asked to choose a name for our new blueprint function library class.

In this guide we used the default name “MyBlueprintFunctionLibrary”. You can change this to your choice of name.

We recommend a clear name with capital letters for each word in the name to follow Unreal Engine 5’s naming convention.

After naming our class and clicking the Create Class button, our project then compiles the new files for us to use. Wait for this to complete before moving on the next section.

Inside your Code IDE

Now that our new class has been created, we can now open our IDE of choice and look at the files Unreal Engine has created for us.

As we chose “MyBlueprintFunctionLibrary” as our class name, we can see that we have two files. A .cpp file for our code, and a .h header file for our declarations both with our chosen name.

Add functions

Now we are ready to add our C++ code to add functionality to our Blueprint Function Library.

For this guide we are making a simple read and write system for strings. This will take our string and save it to a specified file, and can also read a file into a Unreal Engine string.

For your project, you can write the C++ code necessary for your required features.

First in our header file we can see that the engine has generated us a basic file with the correct includes and inheritance for our class.

Next we add our function declaration. We have added a basic function that returns a true or false bool based on if we can save the string to the file or not.

The most important part is to use the static keyword. This makes our function accessible anywhere without an object reference!

We then must add our UFUNCTION macro to make our function visible inside of our blueprint editor.

Next, we repeat the same as before with our loading string from file function. As before it is static with a UFUNCTION macro for blueprint compatibility.

Lastly, we open the .cpp file and add our function code.

This is a simple use of the FFileHelper library in Unreal Engine 5 to allow us to read and write strings to files.

Our Blueprint Function Library is now a powerful example of what we can do when we need access to C++ functionality inside of our blueprints!

Once you have completed this step, compile your project and relaunch the editor.

How to use the C++ Blueprint Function Library in Blueprints

Finally, we can open any blueprint editor and type the name of our new blueprint function libary.

We can see in the actions pop up box that our two “Load String to File” and “Save String to File” C++ functions are now exposed to the blueprints system!

Demonstration

To demonstrate our functions working, we opened the level blueprint, created a BeginPlay event, and connected our new Save String to File C++ Blueprint Library function to it.

We can specify any string to save, and choose a file name.

After running this with “Save Test” as the String to Save and textfile-test.txt as the File Name, we can see in the project /Saved folder our file and string!

Lastly, we can test our Load String from File function inside of the editor the same way.

We have created the loadtest.txt file in the /Saved folder of our project, and written the string “Loading Test” into it and saved.

Inside of the level blueprint we then add our Load String from File C++ Blueprint Function Library function and connected it to a print string node.

This will load of text file into a string and print it to the screen.

As you can see, after playing our project in the editor, our string from inside our file is show on screen!

Conclusion

Now you understand how to use C++ Blueprint Function Libraries in Unreal Engine 5!

The use of these function libraries gives tangible performance improvements and also unlocks the hidden functionality inside of the engine; exposing this to your blueprint code!

Further Reading

Official blueprint function library documentation from Epic Games
Click here to read more of our C++ guides for Unreal Engine

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