CAReplicatorLayer是一个layer容器，会对其中的subLayer进行一些差异处理（它的子layer都可以拷贝）

属性：

//拷贝的次数
@property NSInteger instanceCount;
//是否开启景深效果
@property BOOL preservesDepth;
//当CAReplicatorLayer的子Layer层进行动画的时候，拷贝的副本执行动画的延时
@property CFTimeInterval instanceDelay;
//拷贝副本的3D变换
@property CATransform3D instanceTransform;
//拷贝副本的颜色变换
@property(nullable) CGColorRef instanceColor;
//每个拷贝副本的颜色偏移参数
@property float instanceRedOffset;
@property float instanceGreenOffset;
@property float instanceBlueOffset;
//每个拷贝副本的透明度偏移参数
@property float instanceAlphaOffset;

例子：

    //  背景 layerCAReplicatorLayer * replicatorLayer = [CAReplicatorLayer layer];replicatorLayer.frame = CGRectMake(80, 100, 200, 200);replicatorLayer.cornerRadius = 10;replicatorLayer.backgroundColor = [UIColor colorWithWhite:0 alpha:0.75].CGColor;[self.view.layer addSublayer:replicatorLayer];// 单个layerCALayer *layer = [CALayer layer];layer.frame = CGRectMake(80, 20, 20, 20);layer.backgroundColor = [UIColor redColor].CGColor;[replicatorLayer addSublayer:layer];CABasicAnimation *animation = [CABasicAnimation animation];animation.keyPath = @"transform.scale";animation.fromValue = @(1);animation.toValue = @(0.1);animation.duration = 1.5;animation.repeatCount = MAXFLOAT;[layer addAnimation:animation forKey:nil];// 设置拷贝份数int  number = 15;CGFloat angle = 2 * M_PI / 15;replicatorLayer.instanceCount = number;// 拷贝副本的3D变换replicatorLayer.instanceTransform = CATransform3DMakeRotation(angle, 0, 0, 1);// 设置延时replicatorLayer.instanceDelay = 1.5 / 15;

效果：