I want to use a CAEmitterLayer within a macOS app that is based on SwiftUI.

Problem: The layer itself is perfectly visible, but it doesn’t emit any particles.

→ Here’s my demo project on GitHub

I basically built a NSViewRepresentable for a custom class EmitterNSView: NSView that handles the emitter layer itself.

final class EmitterNSView: NSView {      private let emitterLayer: CAEmitterLayer = {         let layer = CAEmitterLayer()         layer.backgroundColor = NSColor.green.withAlphaComponent(0.33).cgColor         return layer     }()      private let emitterCells: [CAEmitterCell] = {         // https://developer.apple.com/documentation/quartzcore/caemitterlayer         let cell = CAEmitterCell()         cell.name = "someParticle"         cell.birthRate = 10         cell.lifetime = 5.0         cell.velocity = 100         cell.velocityRange = 50         cell.emissionLongitude = 0.0         cell.emissionRange = CGFloat.pi * 2.0         cell.spinRange = 5         cell.scale = 1.0         cell.scaleRange = 0.25         cell.alphaSpeed = 0.25         cell.contents = NSImage(named: "whiteParticle.png")!.cgImage         cell.color = NSColor.systemPink.cgColor         cell.xAcceleration = 4         cell.yAcceleration = 3         cell.zAcceleration = 2         return [cell]     }()      override init(frame frameRect: NSRect) {         super.init(frame: frameRect)         self.wantsLayer = true         self.layer = CALayer()         self.layer?.autoresizingMask = [.layerWidthSizable, .layerHeightSizable]         self.configureEmitterLayer()         self.layer?.addSublayer(self.emitterLayer)     }      required init?(coder: NSCoder) {         fatalError("init(coder:) has not been implemented")     }      override func layout() {         super.layout()         self.configureEmitterLayer()     }      override func updateLayer() {         super.updateLayer()         self.configureEmitterLayer()     }      func configureEmitterLayer() {         self.emitterLayer.frame = self.frame         self.emitterLayer.autoresizingMask = [.layerHeightSizable, .layerWidthSizable]         self.emitterLayer.masksToBounds = false         self.emitterLayer.drawsAsynchronously = true         self.emitterLayer.emitterMode = .points         self.emitterLayer.birthRate = 2         self.emitterLayer.emitterShape = CAEmitterLayerEmitterShape.line         self.emitterLayer.emitterSize = CGSize(width: frame.width * 0.5, height: frame.height * 0.5)         self.emitterLayer.emitterPosition = CGPoint.zero         self.emitterLayer.renderMode = CAEmitterLayerRenderMode.additive         self.emitterLayer.emitterCells = self.emitterCells         self.emitterLayer.zPosition = 10         self.emitterLayer.beginTime = CACurrentMediaTime()         self.emitterLayer.speed = 1.5         self.emitterLayer.emitterCells = self.emitterCells          }  } 

The fact that I can clearly see the green background of the layer within the app indicates that something is wrong with the cells? Feeling lost at this point.

Very similar implementations in UIKit work just fine.

How can I use CAEmitterLayer on macOS within a SwiftUI based app?