下面是api文档的链接 
https://docs.unrealengine.com/latest/INT/API/Runtime/Engine/GameFramework/APawn/index.html 
Pawn is the base class of all actors that can be possessed by players or AI. They are the physical representations of players and creatures in a level.

Pawn是可以被玩家和AI控制（我觉得possessed不贴切）的所有Actor的基础类，他是玩家在Level中的物理和生物表现



ACharacter和ADefaultPawn

看上面的继承结构我们和高兴它的子类大体就分成三个，一个类人的（行走）Pawn，一个默认的Pawn，和一个车轮子Pawn（赛车游戏的福音），太清爽了。

Unreal Interface


Unreal接口文件内包含了两个类，一个是处理反射机制的U开头的类，一个是真正使用的I开头的类，继承接口需要继承I开头的类


Unreal的接口主要有三种形式，仅C++可见接口不受以下三种形式限制：

1.UINTERFACE(MinimalAPI, meta = (CannotImplementInterfaceInBlueprint)) + BlueprintCallable

表示该接口无法在blueprint中被重载，函数必须为虚函数并在接口中实现定义，可以在C++子类中被重载
2.BlueprintCallable, BlueprintImplementableEvent + Blueprintable 并且不带CannotImplementInterfaceInBlueprint

表示该接口只在Blueprint中被重载，C++中不能重载，并且函数不能被声明为虚函数
3.BlueprintCallable, BlueprintNativeEvent + Blueprintable 并且不带CannotImplementInterfaceInBlueprint

表示该接口可以在Blueprint或C++中被重载，并且函数不能被声明为虚函数。在C++中重载的函数需要被命名为原函数+_Implementation，并且为虚函数，在Interface的头文件中会自动生成，因此只需要在继承的子类中声明并定义


确定类是否继承并实现了接口（代码引用自官方文档）
OriginalObject->GetClass()->ImplementsInterface(UReactToTriggerInterface::StaticClass());
// 如果OriginalObject实现了UReactToTriggerInterface，则bisimplemated将为true。

bIsImplemented =
OriginalObject->Implements<UReactToTriggerInterface>();
 //如果OriginalObject实现了UReactToTrigger，bIsImplemented将为true。

IReactToTriggerInterface* ReactingObject =
Cast<IReactToTriggerInterface>(OriginalObject); 
 //如果OriginalObject实现了UReactToTriggerInterface，则ReactingObject将为非空。 ```

Win10源码编译UnrealEngine
背景
准备工作
编译
更新到Epic的最新更改
解决拉取失败

背景
其实从来没有记笔记的习惯，总觉得理解了就行了，奈何年纪大了，有些东西不记一下确实容易忘，复用的时候还要再花同样长的时间重新学习，效率太低了，为了提高生产力还是记一下。
准备工作

创建Epic Games账号
关联Github账号
安装Visual Studio Community 2019

installer中勾选Git，不需要再单独安装Git了，Visual Studio的Git是一样的，而且Program Files里和VS安装目录里都会有git.exe


配置Git

工具-选项-源代码管理中设置使用Git



生成SSH密钥，ssh-keygen -t rsa -C github账号的邮箱

配置GitHub帐户使用SSH公钥，私钥谁也不能给
在Github上Fork UnrealEngine项目到自己账号
Git bash到想要存放UnrealEngine的目录下：

git clone git@github.com:你自己的Github名字/UnrealEngine.git

有可能会报22号端口不可用的错：
Cloning into 'UnrealEngine'...
ssh: connect to host github.com port 22: Connection timed out
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

结合这个链接新建.ssh/config文件，设置端口，还有这个链接里zzqcn的回答

最后我的用户名/.gitconfig和用户名/.ssh/config是这样的：

.gitconfig：
[user]
name = github用户名
email = github邮箱

config：
Host github.com
User git
ProxyCommand connect -S 127.0.0.1:1080 %h 22

这里1080是代理的端口号，具体查一下自己的代理。

还有一个不知道有没有起作用的：C:\Windows\System32\drivers\etc\hosts中添加
151.101.72.249 github.global.ssl.fastly.net
192.30.253.112 github.com

才能得到可以接受的速度：
Receiving objects: 100% (2269007/2269007), 2.79 GiB | 3.34 MiB/s, done.

编译
按照官方说明执行后续步骤
更新到Epic的最新更改
从上游远程拉取希望更新的变更
解决拉取失败
报错：Unable to connect to relay host, errno=10061

github上现有解决方案

Almost Unreal - The Royal Instrumental Orchestra
Babe  come in from the cold
And put that coat to rest
Step inside  take a deep breath
And do what you do best
Yes  kick off them shoes
And leave those city streets
I do believe  love came our way
And fate did arrange for us to meet
I love when you do that
Hocus pocus to me
The way that you touch
You got the power to heal
You give me that look
It's almost unreal
It's almost unreal
Hey  we can't stop the rain
Let's find a place by the fire
Sometimes I feel
Strange as it seems
You've been in my dreams all my life
I love when you do that
Hocus pocus to me
The way that you touch
You got the power to heal
You give me that look
It's almost unreal
It's almost unreal
It's a crazy world out there
Let's hope our prayers are
In good hands tonight
Oh  I love when you do that
Hocus pocus to me
The way that you touch
You got the power to heal
You give me that look
It's almost unreal
It's almost unreal
So unreal
He come you do that
Hocus pocus to me
The way that you touch
You got the power to heal
You give me that look
It's almost unreal
It's almost unreal
It's almost unreal
Do that hocus pocus to me
Do that hocus pocus to me
Do that hocus pocus to me
Do that hocus pocus to me
Do that hocus pocus to me
暂无歌词