UE is a modular architecture, where Engine/Game Project/StandaloneApplication/Plugins are all Modules (Unreal Engine API Reference lists the Modules provided by the Engine). This article analyzes how UE’s Modules are loaded and started via FModuleManager::LoadModule
using the code from FModuleManager
.
Build flow of the Unreal Engine4 project
Symbols count in article: 6.8k Reading time ≈ 17 mins.
UE builds projects through UBT (whether using Build in VS or Compile in the Editor, it eventually calls UBT). UBT and UHT are the cornerstones of the UE toolchain, and due to the vast amount of content, it is impossible to analyze everything at once. Let’s outline the main points now and supplement them later as time allows.
C++ Polymorphism and Virtual Function Table
C++ is a language that supports object-oriented programming (object-oriented Programming), with inheritance and polymorphism (Polymorphic) being its most important features. There has been considerable discussion in previous articles about various aspects of C++ inheritance and class member content. This article primarily investigates one implementation method of C++ polymorphism by the compiler: virtual function tables.
The C++ standard ([IOS/IEC 14882:2014]) states:
Virtual functions support dynamic binding and object-oriented programming. A class that declares or inherits a virtual function is called a polymorphic class.
Note: The C++ standard does not specify how polymorphism is implemented, so the implementation of polymorphism by the compiler is Implementation-defined Behavior
, meaning different compilers may implement polymorphism differently, and different platforms may yield different experimental results.
UE Package Error:ObservedKeyNames.Num()>0
Symbols count in article: 3.4k Reading time ≈ 8 mins.
Recently, I encountered a very strange error during the project packaging:
1 | // package log |
I debugged the UE4 code and analyzed the cause and solution process.
Macro defined by UBT in UE4
UE4 Engine defines many macros and some processing logic within the engine, such as WITH_ENGINE
/WITH_EDITOR
, etc. Some of these are defined by UBT through reading the configurations in *.target.cs
files, and some logic is processed by reading configurations in *.Build.cs
.
I have read some of the UBT code and extracted part of the configuration files (Target.cs
/Build.cs
) parameters and their mutual definitions with MACROs as a quick reference manual.
You can view the parameters in *.Target.cs
here: UnrealBuildSystem/Targets
You can view the parameters in *.Build.cs
here: UnrealBuildSystem/ModuleFiles
UE’s build system documentation: Build Tools
Extract Tor and build Tor Bridge
Tor’s Bridge, if widely disseminated, may get blocked within a few days, so frequently changing it can be a hassle (this reminds me of the days when I modified the hosts file to access Google). Today, I tinkered a bit and built a Tor Bridge on my VPS for personal use. Additionally, I extracted tor from the Tor Browser so that it doesn’t rely on the Tor Browser and can be used with other browsers.
Warning: Deploying a Bridge may increase the probability of the server being blocked.
Use of dynamic link libraries: loading and linking
In some SDK integrations, some platforms provide only the DLL without an import library for us to use. In this case, we can only use code to load the DLL to call functions within it. This article documents two usage methods and analyzes their pros and cons.
Crawl UE API and generate Dash documents with indexes
Use frp to penetrate the intranet
Recently, I thought about a Raspberry Pi gathering dust, so today I experimented with frp for internal network penetration, allowing my Raspberry Pi at home to be accessed via the Internet.
UE and VR Development Technical Notes
Some technical notes written in the daily cursive about UE4 and VR development, as well as some related materials. Previously scattered in imzlp.com/notes, they have been organized today, and future notes will be placed in this article.