Unreal Engine 4.1 Source code

Welcome to the UE4 source code!

This is the source code page for the Unreal Engine on GitHub. With the UE4 source code, you can modify the engine and tools in any way imaginable and share your changes with others!

You can build the editor for Windows and Mac and compile games for Android, iOS, Playstation 4, Xbox One and Linux. Source code for all tools is included as well, such as Unreal Lightmass and Unreal Frontend.

Before continuing, check out this short tutorial video about getting started with the engine code. We also have a programming guide and full API documentation.

We also have a forum section where you can discuss engine source and GitHub. Have fun!! We can't wait to see what you create!!

Getting up and running

Here is the fun part! This is a quick start guide to getting up and running with the source. The steps below will take you through cloning your own private fork, then compiling and running the editor yourself on Windows or Mac. Oh, and you might want to watch our short tutorial video first. Okay, here we go!

Download the source and unzip it to a folder, or create a fork and clone the repository. If you clone, don't forget to switch to the correct branch for this release! (The 'master' branch has unstable code, so you will want to make sure to choose a release branch.)

You should now have an UnrealEngine folder on your computer. All of the source and dependencies will go into this folder. The folder name might have a branch suffix (such as UnrealEngine-4.1), but that's totally fine.

Download the required dependencies files for the latest release: Required_1of2.zip, Required_2of2.zip.

Unzip the dependencies into the UnrealEngine folder alongside the source. Be careful to make sure the folders are merged together correctly. On Mac, we recommend Option + dragging the unzipped files into the UnrealEngine folder, then selecting Keep Newer if prompted.

Okay, platform stuff comes next. Depending on whether you are on Windows or Mac, follow one of the sections below:

Windows

Be sure to have Visual Studio 2013 installed. You can use any desktop version of Visual Studio 2013, including the free version: Visual Studio 2013 Express for Windows Desktop

Make sure you have June 2010 DirectX runtime installed. You don't need the SDK, just the runtime.

You'll need project files in order to compile. In the UnrealEngine folder, double-click on GenerateProjectFiles.bat. It should take less than a minute to complete. On Windows 8, a warning from SmartScreen may appear. Click "More info", then "Run anyway" to continue.

Load the project into Visual Studio by double-clicking on the UE4.sln file.

It's time to compile the editor! In Visual Studio, make sure your solution configuration is set to Development Editor, and your solution platform is set to Win64. Right click on the UE4 target and select Build. It will take between 15 and 40 minutes to finish compiling, depending on your system specs.

After compiling finishes, you can load the editor from Visual Studio by setting your startup project to UE4 and pressing F5 to debug.

One last thing. You'll want to setup your Windows shell so that you can interact with .uproject files. Find the file named UnrealVersionSelector-Win64-Shippping.exe in the UnrealEngine/Engine/Binaries/Win64/ folder and run it. Now, you'll be able to double-click .uproject files to load the project, or right click them to quickly update Visual Studio files.

Mac

Be sure to have Xcode 5.1 installed.

You'll need project files in order to compile. In the UnrealEngine folder, double-click on GenerateProjectFiles.command. It should take less than a minute to complete. You can close the Terminal window afterwards.

Load the project into Xcode by double-clicking on the UE4.xcodeproj file.

It's time to compile the editor! In Xcode, build the UE4Editor - Mac target for My Mac by selecting it in the target drop down in the top left, then using Product -> Build For -> Running. It will take between 15 and 40 minutes, depending on your system specs.

After compiling finishes, you can load the editor from Xcode using the Product -> Run menu command!