Keywords：Warmup Time, no delay, at once, Particle System, 特效, 粒子

Show particle no delay when emitter spawned

默认播放特效时，会有一秒的延迟，如果想让粒子生成后立即播放，需要进行以下设置：
1，点击例子系统编辑界面最右侧的黑色空闲区域

2，然后在Detail面板中找到Warmup Time参数，修改为1。默认为0

新版本中Warmup Time设置为1并不能生效，需要设为0.1。

How to particle’s world location and world rotation

如果想在游戏场景中控制粒子特效的Rotation，需要勾选发射器Required组件中的Use Local Space选项，否则无论设置rotation值多少，其旋转角度始终是默认的初始值。 （查看大图，请复制图片链接在新窗口中打开）

If doesn’t check Use Local Space, particle would stop at spawned location even it be attached to a moveing Actor.

How to let Ribbon Data use velocity of a actor which particle attached it.

Uncheck Use Local Space in base emitter and ribbon data.

Ribbon Data : How to make trail smooth

Solution:
Spawn PerUnit -> Set Unit Scalar to 1.

How to make a emitter lifetime to be eternal

Solution:
Lifetime -> Set Lifetime to 0.f.

How to play Niagara FX using C++
UNiagaraComponent* NiagaraComp = UNiagaraFunctionLibrary::SpawnSystemAtLocation();
UNiagaraComponent* NiagaraComp = UNiagaraFunctionLibrary::SpawnSystemAttached()