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

LenK's answer worked perfectly for me. If anyone is interested, I re-wrote for Obj-C (note I also slightly changed the key frames on fade in):

CAKeyframeAnimation *fadeInAndOutAnimation = [CAKeyframeAnimation animationWithKeyPath:@"opacity"];
fadeInAndOutAnimation.beginTime = CACurrentMediaTime() + beginTime;
fadeInAndOutAnimation.duration = duration;
fadeInAndOutAnimation.keyTimes = @[@0.0, @( 2.0 / 8.0 ), @( 5.0 / 8.0 ), @1.0];
fadeInAndOutAnimation.values = @[@0.0, @1.0, @1.0, @0.0];
fadeInAndOutAnimation.removedOnCompletion = false;
fadeInAndOutAnimation.fillMode = kCAFillModeForwards;