How to make the dynamic lighting better on mobile?

I 'm confused on how to set up the cascaded shadow maps in a movable directional light to get a better effect or performance for mobile devices.
Since it has shadow issues in mobile preview,see the screenshots below:the large black sharp shadows that will move when i move the camera…Thanks very much.

Hello ,

I could attempt give you a quick rundown of how to improve your lighting, but I do not want to overlook any small important details that could be specific to your development.

These two documentation pages provide GREAT information on how to improve your performance while maintaining the quality lighting you desire. Keep in mind the more dynamic your scene becomes, the less it will perform because of hardware limitation.

Mobile Performance Guidelines

Lighting for Mobile Platforms

I hope these pages help you to optimize your project.

Thank you,

Thanks for the reply.However, these docs have not updated yet because they do not have any iinformation on the movable directional light on mobile.(ue 4.5added support for dynamic shadows on mobile).Any other availbale onformation on this?Thanks very much!

No problem ,

The only other information I have at this time for movable directional lights is directly from the forums.

“Dynamic shadows for movable directional lights are now supported on mobile platforms! Shadows are rendered using cascaded shadow maps with up to two cascades.”