Since there is no questions category at Fab, I created this thread to replace it. This is exclusively about this plugin: HostPlugin | Fab
Hello, I have a question about this plugin.
How should the server app be packaged when packaging the game?
From what I understand, it seems like I need to distribute two separate builds: one for the game and one for the server app. Is this correct?
If not, could you provide a detailed explanation of the build process?
No, you only need one Unreal build. You also need a server running the Apatche Tomcat software. In Tomcat you install the server app that I have developed. This is used to exchange the ip addresses and other data of the unreal builds so that they can connect to each other.
The plugin is there so that player 1 presses “Host” in the game and player 2 then plays on player 1’s device. No Unreal Server is required.
I understand. So, what I need to create is a Tomcat server acting as the master server and an Unreal client build, correct?
I have another question. I successfully installed Tomcat and extracted the UnrealHostPlugin.war file inside it. However, in the Web Application Manager, the execution status of UnrealHostPlugin appears as false.
The logs show the following error:
UnsupportedClassVersionError: unrealHostPlugin/servlets/StartupServlet has been compiled by a more recent version of the Java Runtime (class file version 63.0), this version of the Java Runtime only recognizes class file versions up to 55.0.
My Java version is JDK 11. Should I use JDK 17 instead?
Exactly. Tomcat is the master server.
Open JDK 19 or newer and Tomcat 10 or newer. Keep in mind that you can download Java from Oracle for free but are not allowed to use it for free. So if you want to use it productively later. The software and hardware requirements can also be found on the first page of the documentation.
I missed this tutorial while reading other posts online. Thank you so much!
I just want to confirm one last thing. From what I understand, the process for this plugin is:
- Set up the master server using Tomcat and the plugin.
- Integrate the plugin into Unreal.
- In Blueprint, enter my master server’s HTTP URL into the
StartUEGameHostmethod node, while other inputs are received from the player.
Is this correct?
Yes, you can write it like that.
What is missing. You have to define a key (string) on the server and client so that only your own client can connect to the server and not just anyone. And later in productive use, I recommend installing the Apache2 server for encrypted https communication so that this key and other things cannot be read.
At what point does “define a key (string)” apply? Is it related to the ServerAuthorization method in BP, or is it about the token?
I meant the token. Sorry.
Thank you for your response! Now, I will start studying the Apache2 server.
Hi, the Web Application Manager clearly shows that UnrealHostPlugin is running, but I can’t access http://localhost:8080/UnrealHostPlugin. The error message displayed is:
HTTP 404 - Failed to load resource: the server responded with a status of UnrealHostPlugin/:1404() Could this possibly be a domain issue?
Have you tried it with a browser? There is no website in there that is intended for the browser. Try it with the demo project or the demo project build.
Oh, it seems like it’s normal for nothing to appear in the browser. However, I’m still facing issues when trying to host from my project.
In the attached image, only “Stop!” appears. What could be the issue?
What is in authtoken on the server in the web.xml file must be entered in “Server authentication”. I think I need to update the documentation here. I could also have chosen better names for the parameters.
Should I enter “changeMe” for server authentication?
Also, this time I printed out the logs, and I got the message:
“Can not start a new host because another host is still running.”
What did I do wrong? Could it be because I installed and uninstalled Tomcat multiple times?
Yes, but if you install the server online, be sure to enter something proper.
The error message should not play a role. You can also delete the logs and restart the tomcat.
I finally did it! After waiting a bit longer, I was able to connect.
However, after connecting, I checked the UnrealHostPlugin’s session count in the Tomcat Manager, and it still shows 0. Does this not matter?
Glad to hear it runs.
I don’t think it matters. I never use the manager and don’t know what it refers to.
I have one last question.
After successfully connecting, I closed my PIE window and restarted it, but I got the same error:
“Can not start a new host because another host is still running.”
From what I understand, closing the window like that might not be the correct way, or I might need to create a separate process for disconnecting before closing.
Do you think my assumption is correct?
The plugin runs in Unreal. It continues to run when you press stop play. You have to use the stop function to shut down the host. You can set the stop function before the start function. When you are finished with your project you can remove it. The problem will not exist in a build because there is no play button. But your users still need a way to shut down the host.