Lab 057 – Using Opacity Component with Particle Emitters
We can use Opacity Component on an entity with a Particle System to fade out all particles together.
This can be helpful when we need to show and hide a particle system. For example, when deactivating a rain system in a world. We can dial down the opacity, then deactivate the entity once the value reaches zero.
This lab just changes the value of the Opacity Component on the entity with the Particle Emitter Component.
Lab Code
struct Lab057: View {
@State private var value: Float = 1
var body: some View {
RealityView { content in
let subject = Entity()
subject.name = "Particles"
content.add(subject)
var particleSystem = ParticleEmitterComponent()
particleSystem.isEmitting = true
particleSystem.speed = 0.01
particleSystem.emitterShape = .sphere
particleSystem.emitterShapeSize = [0.3, 0.3, 0.3]
particleSystem.mainEmitter.birthRate = 25
particleSystem.mainEmitter.size = 0.1
particleSystem.mainEmitter.color = .constant(.single(.stepRed))
subject.components.set(particleSystem)
} update: { content in
if let subject = content.entities.first?.findEntity(named: "Particles") {
let opacity = OpacityComponent(opacity: value)
subject.components.set(opacity)
}
}
.toolbar {
ToolbarItem(placement: .bottomOrnament, content: {
HStack {
Slider(value: $value,
in: 0.0...1.0,
minimumValueLabel: Image(systemName: "circle"),
maximumValueLabel: Image(systemName: "circle.fill"),
label: {
Text("Opacity")
})
.frame(width: 240)
}
})
}
}
}Support our work so we can continue to bring you new examples and articles.
Download the Xcode project with this and many more labs from Step Into Vision.
Follow Step Into Vision