UE5 C++学习笔记

Log

Log类型ELogVerbosity
- Log
- Warning
- Error
- All

UE_LOG

//单个文件，定义自己的Log类型
DEFINE_LOG_CATEGORY_STATIC(CategoryName,Log,All);

//全局文件定义，需要include头文件
// xxx.h 头文件声明一个Category为extern，避免多个文件使用此头文件时重复声明
DECLARE_LOG_CATEGORY_EXTERN(CategoryName, Log, All)
// xxx.cpp 源文件定义该Category，全局仅需一份
DEFINE_LOG_CATEGORY(CategoryName)

UE_LOG格式化输出

1
2
3

UE_LOG(LogTemp, Warning, TEXT("init"));
UE_LOG(LogTemp, Log, TEXT("Key : %d Value: %s"), Test.key, Test.Value);
GEngine->AddOnScreenDebugMessage(0, 2.0f, FColor::Yellow, TEXT("init"));

Debug

简述UnrealInsights

命名规范

UE4 C++基础 - 编码规范
T 表示模板类
U 表示类继承自 UObject
A 表示类继承自 AActor
S 表示类继承自 SWidget
I 表示抽象接口类
E 表示枚举
b 表示布尔值
F 表示其他不满足上述规则的类

Get

GEngine->getXXX()
GEditor->getXXX()
GEditor->GetEditorWorldContext().World()

Spawn

TArray TMap

Reflection

UE4属性反射小结
- FindField(Target->GetClass(), VarName)
- FloatProp->GetPropertyValue_InContainer(Target)
UE4 C++ 利用反射获取到类、类的成员
UCLASS
UPROPERTY
- EditAnywhere
- VisibleAnywhere
- BlueprintReadWrite
- Category = “Test”
- Meta = (key=value, key=value, …)
- API Doc
UFUNCTION
- BlueprintCallable
- CallInEditor
- API Doc
UENUM
一文搞懂StaticClass、GetClass和ClassDefaultObject
一文搞懂NativeClass、GeneratedClass、BlueprintClass、ParentClass
UE4 从UProperty到FProperty
- 在UE4中，通过特殊的宏，将所需要反射的数据进行标记，从而自动的生成供运行时查询的信息
- FindObject(UClass)
- NewObject(UClass)
- 从4.25开始，此UProperty已完全更改为FProperty。前缀“F”说明其不再继承UObject

Module | Plugin

ModuleManager
UE Build System：Target and Module
Build flow of the Unreal Engine4 project

Engine Module

API

Core
- 基础数据类型：int32 FString float
- 数学函数，结构体：FMath FVector
- 容器：TArray TList TMap
CoreUObject
- 基础类：UObject UClass UProperty UPackage
- 对象内存分配函数：ConstuctObject FindObject Cast
Engine
- 场景对象、组件：AActor APawn UActorComponent
- 关卡、世界、玩家：UWorld ULevel UPlayer
- 模型、纹理、材质：UTexture UMaterial UStaticMesh
Slate

UObject

[UE4 UObject] 对象概念
UClass::GetDefaultObject() 获取到的为类的 CDO 对象
CDO 对象的主要作用就是用于为类提供默认值
UObject::GetOuter() 获取自己的 Outer 对象
一个对象的 Outer 称为这个对象的父对象，而自己就称为 Outer 对象的子对象
仅能在 UObject 的 Native 构造函数中，调用自己的 UObject::CreateDefaultSubobject() 为自己创建默认子对象
UPackage 对象对应于磁盘上的一个 .uasset 资源文件，或全局临时包
《InsideUE4》目录
《InsideUE4》UObject（一）开篇
《InsideUE4》GamePlay架构（一）Actor和Component
使UObject能够进行Tick

Editor

String

UE4 C++基础 - 字符串和本地化
FString 属于可变字符串
FName FText 属于不可变字符串，创建后内容不能改变
FName 不区分大小写，主要用于标识资源路径，它的优点就是查找和访问速度快
FString转换至FName时会丢失原始字符串的大小写信息
FText 主要用于文本本地化
格式化
- FString::Printf(TEXT(“FormatString:\n%s%s%s”), *A, *B, *Plus);

Thread

Pointer

UE4随笔：UE4智能指针

GC

UE4 垃圾回收

Tools

Third Party C++ Library

UnrealMeshProcessingTools
Interactive Mesh Processing with libigl in Unreal Engine 4.24
UE4链接第三方库的具体使用和演示
UE4链接第三方库（lib和dll）
UE4中使用第三方库
修改UE源码之配置第三方库
- Engine\Source\ThirdParty
  - add
    - PublicAdditionalLibraries.Add(XXX + “cublas.lib”)
    - PublicDelayLoadDLLs.Add(“cublas64_11.dll”)
    - RuntimeDependencies.Add(XXX + “bin/“ + “cublas64_11.dll”)
    - PublicDefinitions.Add(“NV_CUDA=1”)
  - using
    - AddEngineThirdPartyPrivateStaticDependencies(Target, “CUDA_V11”)

Summary

信息是一种能量，只有足够的信息，才能达到质变（Epic大钊）

Build Cmd

UE项目工程

set engine=D:\Software\UE_5.0
set project=D:\Work\Git\Library\PCG\PCG.uproject
set UBT=%engine%\Engine\Binaries\DotNET\UnrealBuildTool\UnrealBuildTool
set Build=%engine%\Engine\Build\BatchFiles\Build.bat

cd /d %engine%
# VisualStudio工程
%UBT% -projectfiles -project=%project% -game -engine -progress -2019
# VScode工程
%UBT% -projectfiles -vscode -project=%project% -game engine -progress -2022
# Editor Development编译模式
%Build% XXXEditor Win64 Development %project% -waitmutex

避免引擎编译时 “Waiting for ‘git status’ command” 的方法

UE源码工程

@echo off

set UE5=%~dp0
set UBTProject=%UE5%Engine\Source\Programs\UnrealBuildTool\UnrealBuildTool.csproj
set UBT=%UE5%\Engine\Binaries\DotNET\UnrealBuildTool\UnrealBuildTool

cd /d %UE5%
@REM compile UBT
dotnet build --configuration Development %UBTProject%
@REM generate projectfiles
%UBT% -projectfiles -vscode -engine -dotnet

RunUAT编译

unreal-automation-tool
- RunUAT.bat -List
- RunUAT.bat BuildGame -Help

UE4中使用Cmd升级插件版本

1	`RunUAT.bat BuildPlugin -plugin="D:\xxx.uplugin" -package="D:\xxx"`

UE4 Slate独立引用程序
- 应用程序依赖特定文件结构和Shader着色器
- 建议直接打包运行器，作为已经配置完成的一栏
- RunUAT脚本工具打包
- dotnet工具
- AutomationTool
- BuildGraph

Reference

Geometry

Landscape

FHoudiniLandscapeTranslator::ImportLandscapeData => SetMaskLayer
FHoudiniLandscapeTranslator::BackupLandscapeToImageFiles => ExportHeightLayer
FHoudiniLandscapeTranslator::CreateOrUpdateLandscapeLayerData
- ULandscapeLayerInfoObject* LayerInfo = GetLandscapeLayerInfoForLayer()
- LayerInfo = FindOrCreateLandscapeLayerInfoObject()
FLandscapeLayer
- OnGetImportLayerCreateMenu //GUI Create
  - OnImportLayerCreateClicked
Process
- ULandscapeLayerInfoObject => create layerInfo package
- Switch Material
  - Import Layer from texture
  - Find or Create layerInfo
  - set layerInfo
    - FHoudiniLandscapeTranslator::OutputLandscape_GenerateTile
    - TArray LayerInfos;
    - for (const auto& ImportLayerInfo : LayerInfos)
      - LandscapeActor->EditorLayerSettings.Add(FLandscapeEditorLayerSettings(ImportLayerInfo.LayerInfo))
  - create layerInfo
    - FHoudiniLandscapeTranslator::CreateOrUpdateLandscapeLayerData
    - FHoudiniLandscapeTranslator::FindOrCreateLandscapeLayerInfoObject
ALandscapeProxy
- ULandscapeInfo *LandscapeInfo = Landscape->GetLandscapeInfo();
ALandscape : public ALandscapeProxy
- Landscape = World->SpawnActor()
- Landscape->Import()
- ULandscapeInfo *LandscapeInfo = Landscape->GetLandscapeInfo();
- LandscapeInfo->UpdateLayerInfoMap(Landscape);
- Landscape->RegisterAllComponents();
Engine\Source\Editor\LandscapeEditor\Private\LandscapeEditorDetailCustomization_ImportLayers.cpp
Engine\Source\Editor\LandscapeEditor\Private\LandscapeEditorDetailCustomization_ImportExport.cpp
Engine\Source\Editor\LandscapeEditor\Private\LandscapeEditorDetailCustomization_TargetLayers.cpp
- OnTargetLayerDeleteClicked
The import size (505×505) does not match the current Landscape extent (0×0), if you continue it will be padded/clipped to fit
Engine\Source\Editor\LandscapeEditor\Private\LandscapeEdMode.cpp
- FEdModeLandscape::ChangeComponentSetting
  - TMap<FGuid, TArray> HeightDataPerLayers;
  - TMap<FGuid, TArray> ImportMaterialLayerInfosPerLayers;
  - auto ExtractHeightmapWeightmapContent = [&](TArray& OutHeightData, TArray& OutImportMaterialLayerInfos)
  - if (HasLandscapeLayersContent()) // edit layers
    - ExtractHeightmapWeightmapContent(HeightData, ImportMaterialLayerInfos);
    - ImportMaterialLayerInfosPerLayers.Add(FGuid(), MoveTemp(ImportMaterialLayerInfos)); // add data
    - NewLandscape->Import(FGuid::NewGuid(), NewMinX, NewMinY, NewMaxX, NewMaxY, NumSubsections, SubsectionSizeQuads, HeightDataPerLayers, *OldLandscape->ReimportHeightmapFilePath, ImportMaterialLayerInfosPerLayers, ELandscapeImportAlphamapType::Additive, LandscapeLayers);
    - Import // create new landscape components
      - Import(const FGuid& InGuid, int32 InMinX, int32 InMinY, int32 InMaxX, int32 InMaxY, int32 InNumSubsections, int32 InSubsectionSizeQuads, const TMap<FGuid, TArray>& InImportHeightData, const TCHAR* const InHeightmapFileName, const TMap<FGuid, TArray>& InImportMaterialLayerInfos, ELandscapeImportAlphamapType InImportMaterialLayerType, const TArray* InImportLayers = nullptr);
      - const TMap<FGuid, TArray>& InImportMaterialLayerInfos
      - ALandscapeProxy::Import
        
        Source\Runtime\Landscape\Private\LandscapeEdit.cpp
    - Import // Houdini Engine Import Method
      - FHoudiniLandscapeTranslator::UpdateLandscapeMaterialLayers(ALandscape* InLandscape,const TArray& LayerInfos)

Foliage || Landscape

FoliageType
- LandscapeLayers
Source\Editor\FoliageEdit\Private\FoliageEdMode.cpp
- GetMaxHitWeight()
  - ULandscapeComponent* HitLandscape
  - float HitWeight = HitLandscape->GetLayerWeightAtLocation(Location,LayerName,LayerCache)

Unreal

#Unreal #C++ #UE

UE5 C++学习笔记

https://automask.github.io/wild/2022/11/25/log/P_UE_C++_2.0/

作者

Kyle Zhou

发布于

2022年11月25日

许可协议

UE5 Slate C++ 笔记下一篇