Unreal Engine Standalone Plugin Builder

BuildPlugin.bat

:: Copyright (c) Solessfir under MIT license

:: This batch file builds an Unreal Engine plugin
:: Place it near .uplugin file and run it

@echo off
setlocal EnableDelayedExpansion
title Build Plugin

:: Enable ANSI color support
reg add HKCU\Console /v VirtualTerminalLevel /t REG_DWORD /d 1 /f >nul 2>&1

:: Define Colors
for /f "delims=" %%a in ('powershell -NoProfile -Command "[char]27"') do set "ESC=%%a"
set "Colors_Red=!ESC![91m"
set "Colors_Green=!ESC![92m"
set "Colors_White=!ESC![97m"
set "Colors_Reset=!ESC![0m"

:: Configuration
set "RootDirectory=%~dp0"
set "RootDirectory=%RootDirectory:~0,-1%"
set "TargetPlatform=Win64"
set "PushdDone=0"

:: 1. Locate Plugin
if exist "%RootDirectory%\*.uplugin" (
    set "PluginDir=%RootDirectory%"
) else if exist "%RootDirectory%\..\*.uplugin" (
    set "PluginDir=%RootDirectory%\.."
) else (
    echo !Colors_Red!Error: No .uplugin file found.!Colors_Reset!
    goto :ExitWithPause
)
pushd "%PluginDir%"
set "PushdDone=1"
for %%i in ("*.uplugin") do set "UpluginFile=%%~fi" & set "PluginName=%%~ni"

:: 2. Extract Engine Version
set "RawVersion="
for /f "tokens=2 delims=:" %%a in ('findstr /i "EngineVersion" "%UpluginFile%"') do set "RawVersion=%%a"

:: Clean string (remove quotes, spaces, commas)
if defined RawVersion (
    set "RawVersion=!RawVersion:"=!"
    set "RawVersion=!RawVersion:,=!"
    set "RawVersion=!RawVersion: =!"
) else (
    echo !Colors_White!EngineVersion not found in .uplugin - searching for latest installed Unreal Engine...!Colors_Reset!
    set "LatestShortVersion="
    for /f "tokens=*" %%a in ('reg query "HKLM\SOFTWARE\EpicGames\Unreal Engine" 2^>nul ^| findstr /r "\\[0-9]"') do (
        set "FullKey=%%a"
        set "LatestShortVersion=!FullKey:HKEY_LOCAL_MACHINE\SOFTWARE\EpicGames\Unreal Engine\=!"
    )
    if defined LatestShortVersion (
        set "RawVersion=!LatestShortVersion!"
        echo Using: !Colors_White!!RawVersion!!Colors_Reset!
    ) else (
        echo !Colors_Red!Error: No Unreal Engine installation found.!Colors_Reset!
        goto :ExitWithPause
    )
)

:: 3. Locate Engine Installation
set "EngineDir="

:: A. Try exact match (Source Builds/GUIDs via HKCU)
reg query "HKCU\Software\Epic Games\Unreal Engine\Builds" /v "{%RawVersion%}" >nul 2>&1
if !errorlevel! equ 0 (
    for /f "skip=2 tokens=2*" %%a in ('reg query "HKCU\Software\Epic Games\Unreal Engine\Builds" /v "{%RawVersion%}"') do set "EngineDir=%%b"
)

:: B. Try Standard Installation (HKLM) - Requires Major.Minor format (e.g. 5.3)
if not defined EngineDir (
    :: Parse Major.Minor from the raw version (e.g., 5.3.2 -> 5.3)
    for /f "tokens=1,2 delims=." %%a in ("!RawVersion!") do set "ShortVersion=%%a.%%b"

    reg query "HKLM\SOFTWARE\EpicGames\Unreal Engine\!ShortVersion!" /v "InstalledDirectory" >nul 2>&1
    if !errorlevel! equ 0 (
        for /f "skip=2 tokens=2*" %%a in ('reg query "HKLM\SOFTWARE\EpicGames\Unreal Engine\!ShortVersion!" /v "InstalledDirectory"') do set "EngineDir=%%b"
    )
)

:: C. Check Relative Path
:: EngineDir must be set to the engine root (parent of the Engine\ folder) so the
:: RunUAT path below resolves correctly as %EngineDir%\Engine\Build\BatchFiles\RunUAT.bat
if not defined EngineDir (
    if exist "%PluginDir%\..\..\Engine\Build\BatchFiles\RunUAT.bat" set "EngineDir=%PluginDir%\..\.."
)

if not defined EngineDir (
    echo !Colors_Red!Error: Unreal Engine installation not found for version: %RawVersion%!Colors_Reset!
    goto :ExitWithPause
)

set "RunUAT=%EngineDir%\Engine\Build\BatchFiles\RunUAT.bat"

if not exist "!RunUAT!" (
    echo !Colors_Red!Error: RunUAT.bat not found at:!Colors_Reset!
    echo !RunUAT!
    goto :ExitWithPause
)

:: 4. Locate Host Project (.uproject two levels up - optional, needed to resolve external plugin dependencies)
set "UprojectFile="
for %%i in ("%PluginDir%\..\..\*.uproject") do set "UprojectFile=%%~fi"

:: 5. Build Plugin
cls
echo !Colors_Green!:: Building Plugin: %PluginName% ::!Colors_Reset!
echo Version: !Colors_White!%RawVersion%!Colors_Reset!
echo Engine:  !Colors_White!%EngineDir%!Colors_Reset!
if defined UprojectFile (
    echo Project: !Colors_White!%UprojectFile%!Colors_Reset!
)
echo:

set "OutputDir=%PluginDir%\Build"

:: Clean previous build
if exist "%OutputDir%" (
    echo Cleaning previous build...
    rd /s /q "%OutputDir%" >nul 2>&1
)

:: Execute build:
:: - With host project: UAT BuildPlugin isolates the plugin but cannot compile external plugin
::   dependencies in its restricted HostProject environment. Use Build.bat against the real
::   project instead (all deps resolve naturally), then package the output manually.
:: - Standalone: UAT BuildPlugin works fine for self-contained plugins.
if defined UprojectFile (
    set "BuildBat=%EngineDir%\Engine\Build\BatchFiles\Build.bat"
    call "!BuildBat!" UnrealEditor Win64 Development -Project="%UprojectFile%" -plugin="%UpluginFile%" -noubtmakefiles -nohotreload
    set "BuildResult=!errorlevel!"

    if !BuildResult! equ 0 (
        echo:
        echo Packaging...
        robocopy "%PluginDir%" "%OutputDir%" /E /XD "Source" /XD "Intermediate" /XD "Build" /XF "*.pdb" /XF "*.bat" /NJH /NJS >nul
    )
) else (
    call "!RunUAT!" BuildPlugin -Plugin="%UpluginFile%" -Package="%OutputDir%" -Rocket -TargetPlatforms=%TargetPlatform%
    set "BuildResult=!errorlevel!"

    :: Clean up temp HostProject from the output package
    if exist "%OutputDir%\HostProject" (
        rd /s /q "%OutputDir%\HostProject" >nul 2>&1
    )
)

echo:
if !BuildResult! neq 0 (
    echo !Colors_Red!Build Failed. Check log above.!Colors_Reset!
) else (
    echo !Colors_Green!Build Successful.!Colors_Reset!
    echo Output: !Colors_White!%OutputDir%!Colors_Reset!
)

:ExitWithPause
if "%PushdDone%"=="1" popd
pause
exit /b