Animating SCNCamera.fStop with pro… | Apple Developer Forums

Animating SCNCamera.fStop with property key path doesn't work, only inside implicit SCNTransaction

This code strangely doesn't animate the fStop:

Code Block cameraNode.camera!.wantsDepthOfField = true
cameraNode.camera!.focusDistance = 2
let animation = CABasicAnimation(keyPath: "fStop")
animation.toValue = 0.5
animation.duration = 0.3
cameraNode.camera!.addAnimation(animation, forKey: nil)

Code Block
cameraNode.camera!.wantsDepthOfField = true
cameraNode.camera!.focusDistance = 2

let animation = CABasicAnimation(keyPath: "fStop")
animation.toValue = 0.5
animation.duration = 0.3
cameraNode.camera!.addAnimation(animation, forKey: nil)

while this one does:

Code Block SCNTransaction.begin()
SCNTransaction.animationDuration = 0.3
cameraNode.camera!.fStop = 0.5
SCNTransaction.commit()

Code Block
SCNTransaction.begin()
SCNTransaction.animationDuration = 0.3
cameraNode.camera!.fStop = 0.5
SCNTransaction.commit()

Why?