I want to display different content in portrait and landscape orientations. How can i detect in BluePrints that user (on mobile) have changed orientation?
You can map/bind input from mobile device’s Tile/Accel/Gravity in Edit->Project Settings->Engine->Input.
But I can find where it detects orientation change event like in android sdk, so maybe ask this on AnswerHub and they could add this event on next release.
(Or unless you can code that input event and expose it for blueprint.)