As a suggestion, I spent an entire day playing around with a bunch of bezier paths, some complicated, some very simple, until it hit me, the direction of the winding would affect the result.
So, it might be worth mentioning, if you're not seeing any results using bezier paths, try using reversing (Swift)/beziePathByReversingPath (Objective C) and use the resulting path
As a suggestion, I spent an entire day playing around with a bunch of bezier paths, some complicated, some very simple, until it hit me, the direction of the winding would affect the result.
So, it might be worth mentioning, if you're not seeing any results using bezier paths, try using
reversing(Swift)/beziePathByReversingPath(Objective C) and use the resulting path