Hello world! For example, is this is a good solution for aspect ratio problem.
Mobile game in Vertical orientation. All game assets draw in 16:9 ratio. All playable elements placed in 4:3 area of this 16:9 asset. When app is started in phone/tablet with aspect ration not equal to 16:9, i cut some part of top and bottom view. Here is an example what i try to explain.
green frame indicate background which was originally drew in 16:9, When app stars, we scale camera like in gray area ( this area is an actual screen size of phone/tablet in which my app is run ), and cut red parts of asset.
This is my idea how to handle problem with different aspect ratios, but, maybe UE4 has another solution?