UE4【C++】子弹伤害系统使用

可能很多初学者如果想知道ue4的这种伤害系统如何使用起来会有点迷茫。

我自己做了demo给大家参考下。

首先要有个子弹类。

.h代码如下

 1 uclass()
 2 class snvrclayshooting_api aprojectile : public aactor
 3 {
 4     generated_body()
 5     
 6 public:    
 7     // sets default values for this actor's properties
 8     aprojectile();
 9 
10     uproperty(visibleanywhere, blueprintreadwrite, category = "projectile")
11         ustaticmeshcomponent* projectilemesh;
12 
13     uproperty(visibleanywhere, blueprintreadwrite, category = "projectile")
14         uparticlesystemcomponent* launchparticle;    //烟火，开枪时
15 
16     uproperty(visibleanywhere, blueprintreadwrite, category = "projectile")
17         uprojectilemovementcomponent *projectilemovementcomponent = nullptr;
18 
19 protected:
20     // called when the game starts or when spawned
21     virtual void beginplay() override;
22 
23     ufunction()
24         void onhit(uprimitivecomponent* hitcomponent, aactor* otheractor, uprimitivecomponent* othercomp, fvector normalimpulse, const fhitresult& hit);
25 
26 public:    
27     // called every frame
28     virtual void tick(float deltatime) override;
29 
30     ufunction(blueprintcallable, category = "projectile_fun")
31         void launchprojectile(fvector speed);
32     
33 };

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.cpp代码如下

 1 aprojectile::aprojectile()
 2 {
 3      // set this actor to call tick() every frame.  you can turn this off to improve performance if you don't need it.
 4     primaryactortick.bcanevertick = true;
 5 
 6     projectilemovementcomponent = createdefaultsubobject<uprojectilemovementcomponent>(fname("projectilemovement"));    //生成组件
 7     projectilemovementcomponent->bautoactivate = false;        //自动飞行调成false
 8 
 9     projectilemesh = createdefaultsubobject<ustaticmeshcomponent>(fname("projectilemesh"));
10     rootcomponent = projectilemesh;
11     projectilemesh->setnotifyrigidbodycollision(true);
12     projectilemesh->setvisibility(true);
13 
14     launchparticle = createdefaultsubobject<uparticlesystemcomponent>(fname("launchparticle"));
15     launchparticle->setupattachment(projectilemesh);    //将粒子效果绑定在根结点上（即projectilemesh）
16     launchparticle->setautoactivate(true);                //创建好就启动
17 
18     projectilemesh->oncomponenthit.adddynamic(this, &aprojectile::onhit);
19 
20     initiallifespan = 5.0f;
21 }
22 
23 // called when the game starts or when spawned
24 void aprojectile::beginplay()
25 {
26     super::beginplay();
27     
28 }
29 
30 // called every frame
31 void aprojectile::tick(float deltatime)
32 {
33     super::tick(deltatime);
34 
35 }
36 void aprojectile::launchprojectile(fvector speed) 
37 {
38     projectilemovementcomponent->setvelocityinlocalspace(speed);
39     projectilemovementcomponent->activate();    //可以飞行了
40 }
41 //碰撞后发生的事件
42 void aprojectile::onhit(uprimitivecomponent* hitcomponent, aactor* otheractor, uprimitivecomponent* othercomp, fvector normalimpulse, const fhitresult& hit)
43 {
44     ue_log(logtemp, warning, text("aprojectile::onhit--otheractor.name=%s"),*otheractor->getname());    //撞击后给个提示
45 
46     projectilemesh->setnotifyrigidbodycollision(false);    //碰撞之后再也不发生碰撞事件
47     //collisionmesh->destroycomponent();    //不是destroyactor，component是单一一个
48 
49     //受伤害源otheractor的takedamage()会被调用
50     ugameplaystatics::applypointdamage(otheractor, 10.0f, getactorlocation(), hit,null,null, udamagetype::staticclass());
51 
52     destroy();
53 }

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伤害的入口从onhit看出，调用了ugameplaystatics::applypointdamage；

第一个参数就是受伤害源，ue4的伤害系统会调用受伤害源的takedamege接口；

此时子弹有了伤害力，那么受伤害源就要被伤害；

每个actor都有这个接口virtual float takedamage(float damageamount, struct fdamageevent const& damageevent, class acontroller* eventinstigator, aactor* damagecauser);

只要重写这个接口，写上自己的处理逻辑。

受伤害源部分代码如下：

 1 float adamagedactor::takedamage(float damageamount, struct fdamageevent const& damageevent, class acontroller* eventinstigator, aactor* damagecauser)
 2 {
 3     float actuallyapplied = 0.0f;
 4 
 5     maxhp -= damageamount;
 6 
 7     ue_log(logtemp,warning,text("adamagedactor::takedamage--maxhp=%f"),maxhp);
 8 
 9     actuallyapplied = fmath::clamp<float>(maxhp, 0.0f, 100.0f);
10 
11     return actuallyapplied;
12 }

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以上就是简单的使用ue4的伤害系统。