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Unreal Editor

note

As of writing, PAYDAY 3 uses Unreal Engine 4.27. If PAYDAY 3 upgrades to Unreal Engine 5, this documentation will become obsolete until updated.

Intro​

To begin using the Unreal Editor, you must ensure you have version 4.27 installed. You can either compile it yourself from source or you can install it through the Epic Games Launcher.

note

If you do not wish to use the PAYDAY3 modkit, you must make sure your project is called PAYDAY3.

Not using the PAYDAY3 modkit is unsupported and not recommended as you do not have access to PAYDAY3's data formats.

Testing your mod​

Setting up PAYDAY 3 to allow your PAK to be loaded​

As of writing, PAYDAY 3 will check if your PAK file has a generated signature, this can be bypassed by passing -fileopenlog to PAYDAY 3 when it launches.

You can set this easily by putting the launch option in the steam launch options Steam Launch Options

Cooking​

PAYDAY 3 requires all of its files to be cooked, so you must cook your game files everytime you want to package and test your mod.

You can cook your game files by opening the File menu and clicking Cook Content for Windows. Once cooked, your files will be located at {UE4ProjectDir}/Saved/Cooked/WindowsNoEditor/.

UE4 Cook

Packaging​

When packaging your game files, you must be incredibly careful not to package any dummy assets used by the modkit. If you package any dummy assets, the game could crash or create other obscure issues. In order to package your game files, you must make sure you have cooked your files first.

Once cooked, you must copy out all the files your mod replaces or adds, like maps, models, textures, etc. When copying you must make sure the folder structure stays the same. For example, a custom map at {UE4ProjectDir}/Saved/Cooked/WindowsNoEditor/PAYDAY3/Maps/CoolMap/CoolMap.umap should be copied to {MyNewMod_P}/PAYDAY3/Maps/CoolMap/CoolMap.umap.

Once all your files are copied, you must now package the MyNewMod_P with the tool of your choice. The tool you use is up to personal preference, but the recommended tool is repak by trumank

  1. Add repak to your PATH or drop the exe next to the folder you want to pak (MyNewMod_P in this case)
  2. Open a cmd or powershell window in the folder by holding the Shift key and right clicking on the explorer background, then select in the context menu select "Open [command or powershell] window here".
  3. Run repak.exe pack MyNewMod_P to pack MyNewMod_P into MyNewMod_P.pak.
C:\PD3_Modding> repak.exe pack PackagingStagingFolder
Packed 2 files to PackagingStagingFolder.pak
  1. To verify proper packaging, you can run repak.exe list MyNewMod_P.pak and it will list all the paths e.g.:
C:\PD3_Modding> repak.exe list MyNewMod_P.pak
PAYDAY3/Maps/CoolMap/CoolMap.umap
PAYDAY3/Maps/CoolMap/CoolMap.uexp

Once packaged, place your pak files in {InstallFolder}/PAYDAY3/Content/Paks/~mods/ (create ~mods if it does not exist) and your mod should be loaded by PAYDAY 3.

Packaging for use with the launcher

It's highly recommended to create a pd3mod before you upload your mod for users to install. See the documentation on Packaging for more info.

Load Order​

Unreal Engine loads files in PAKs in alphabetical order, so if you want your mod to load after another mod, you must make sure your mod's name comes after the other mod's name alphabetically. It is best to prefix your mod's name with the letter z, ensuring it will load last and overwrite any file you need it to.

Viewing PAYDAY 3's PAK files​

In order to view PAYDAY 3's PAK files, you must first obtain the AES key. While we cannot distribute the AES key ourselves, you can dump it very easily. Once the AES key is obtained, you can open PAYDAY 3's files in the program of your choice such as FModel.