How to Change a Project to use the Engine Source Code

It is sometimes desirable to change an existing Unreal Engine project to use the engine source code to:

  • gain access to more build configurations, such as debug versions of engine code
  • to customize the engine code

To make the change you need to:

  • download a version of the engine code, following the instructions in BuildFromSource.html to select a branch and build it
  • register your source build so that it appears as an option when you right-click a .uproject file. To do this use Explorer to locate and execute this file under your source build directory:


  • right-click you game project .uproject file and select the source build engine:


  • changing to the source build will automatically regenerate the .sln file