CoreAnimation - Opacity Fade In and Out Animation Not Working

Question

I\'m attempting to create a fairly simple CoreAnimation for use in an AVComposition. My goal is to create a CALayer which, through various sublayer

Answer 1

The point is key name. You have to set the opacity key.

layer.add(animation, forKey: nil)         // Not Working
layer.add(animation, forKey: "opacity")   // Working

Check the sample code. I tested in Swift 4

    let animation                   = CAKeyframeAnimation()
    animation.duration              = 1.53
    animation.autoreverses          = false
    animation.keyTimes              = [0, 0.51, 0.85, 1.0]
    animation.values                = [0.5, 0.5, 1.0, 0.5]
    animation.beginTime             = 0
    animation.isRemovedOnCompletion = false
    animation.fillMode              = kCAFillModeBoth
    animation.repeatCount           = .greatestFiniteMagnitude
    layer.add(animation, forKey: "opacity")