How to disable loop for ParticleEmitterComponent on visionOS?

Question

In Reality Composer Pro there is a flag to toggle the loop of the particle system. In code I couldn't find a .loop value on the ParticleEmitterComponent - does anyone know how else I can disable the looping there?

Answer 1

To disable the loop you have to set the .timing value to once like this:

var particles = ParticleEmitterComponent()
particles.timing = .once(warmUp: 0, emit: .init(duration: 1))

Answer 2

Besides the .once(...) case of the timing enum, you can use the fantastic burst() instance method which emits burstCount particles on the next update call. Here's the code:

import SwiftUI
import RealityKit

struct ContentView : View {
    @State var particles = ParticleEmitterComponent()
    let entity = Entity()
    
    var body: some View {
        VStack {
            Button("Burst") {
                particles.isEmitting = false     // important

                entity.components.remove(ParticleEmitterComponent.self)
                entity.components[ParticleEmitterComponent.self] = pSystem()
            }
            RealityView { content in
                content.add(entity)
            }
        }
    }       
    func pSystem() -> ParticleEmitterComponent {
        particles.emitterShape = .sphere
        particles.burstCount = 1500
        particles.burst()
        return particles
    }
}