n00neimp0rtant

// iOS 9 allows you to animate between visual effects, which gives you the
// ability to manipulate the blur radius. this can be useful for animating
// a backdrop for a custom modal, and with a few tricks, can even be set
// indirectly, allowing you to "scrub" between them back and forth with
// a gesture, just like when you pull down Spotlight.

// these are the two effects you want to transition between
UIVisualEffect *startEffect = nil; // "nil" means no blur/tint/vibrancy (plain, fully-transparent view)
UIVisualEffect *endEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];