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Linking external dlls or libraries

All In One Sample on a Plugin that builds its own Third Party Lib: https://github.com/ue4plugins/MotionCueingInterface

Dynamic DLL https://wiki.unrealengine.com/Linking_Dlls

Plugins Overview & Third Party Overview: https://www.slideshare.net/GerkeMaxPreussner/plugins-thirdparty-sdks-in-ue4

Add header only (no dll/lib) third party stuff:

Linking 3rd Third Party Static Library:

https://wiki.unrealengine.com/Linking_Static_Libraries_Using_The_Build_System

https://answers.unrealengine.com/questions/243103/how-to-i-link-a-third-party-library-using-the-unre.html

https://wiki.unrealengine.com/Integrating_OpenCV_Into_Unreal_Engine_4 PublicDelayLoadDLLs.Add(“opencv_calib3d2410d.dll”); PublicAdditionalLibraries.Add(“opencv_video2410d.lib”);

NOTE: IF YOU NEED TO JUST LINK AGAINST AN EXTERNAL SET OF HEADER FILES, USE PrivateIncludePathModuleNames OR PublicIncludePathModuleNames.

IF A HEADER NEEDS TO INCLUDE EXTERNAL HEADER AND THE HEADER IS IN A PUBLIC FOLDER, YOU HAVE TO USE PublicIncludePathModuleNames

Notes:#

Module Types#

•Developer – for development only •Editor – for Unreal Editor only •Runtime – for anything •Programs – for standalone programs •Third Party – for external code & libs Note: The UE4 EULA prohibits inclusion of Editor modules in shipping games

Structure of Modules

  • Private folder
  • Internal implementation
  • Module initialization
  • Pre-compiled header
  • Public folder
  • Interfaces
  • Exported Types
  • Build.cs file

Https

PrivateIncludePaths

  • Sub-folders inside your module’s Private folder

PublicIncludePaths

  • Sub-folders inside your module’s Public folder (not needed)

PrivateIncludePathModuleNames

  • Modules whose public headers your module’s private implementation includes, but doesn’t link to PublicIncludePathModuleNames

  • Modules whose public headers your module’s public interface includes, but doesn’t link to

PrivateDependencyModuleNames

  • Modules that your module’s private implementation requires for compiling and linking

PublicDependencyModuleNames

  • Modules that your module’s public interface requires for compiling and linking DynamicallyLoadedModuleNames

  • Modules that are loaded at run-time via ModuleManager (this is to ensure that they get compiled)

More options in RulesCompiler.cs

PublicLibraryPaths

  • Paths to folders containing additional libraries

PublicAdditionalLibraries

  • Additional libraries (.lib or .a files) to link against

PublicFrameworks

  • Additional XCode frameworks (iOS, macOS only)

PublicWeakFrameworks

  • Weak frameworks (for OS transition)

PublicAdditionalShadowFiles

  • Files that need to be copied for remote compilation

RuntimeDependencies

  • Runtime dependencies to be staged for a packaged build

Structure of Plug-ins

  • One or more modules

  • Plug-in descriptor

  • Content (optional)

  • Resources (optional)

  • Plug-in Descriptor
  • Json file {PluginName.uplugin}
  • Inside root of plug-in directory
    • Contains:
    • Version information
    • User friendly description
    • Module loading rules

Third-Party Libraries

Structure of Engine Dependencies

•Located in /Engine/Source/ThirdParty

•Each has its own Build.cs file

• Just like any other module

• Public includes (for headers to be

compiled into dependent modules)

• Public libraries (for libraries to be

linked into dependent modules)

• Optional pre-processor definitions

Building Engine Dependencies

•Source code is often included, but…

• We provide pre-compiled libs for everything

• UBT never compiles them when building your projects

•Internally, we pre-compile the libraries using…

• BuildThirdPartyLibs UAT script (automated)

• Batch files and shell scripts (manual)

• Specialized UAT scripts (i.e. for PhysX)

•Sometimes there are text files with instructions

Structure of Plug-in Dependencies

•Same as Engine third-party dependencies

•Same build rules


Last update: November 14, 2019