How to compute GI at runtime using enlighten in unity5

The scene is nice at the beginning of the game because of the precompute realtime GI.
But if you change the gameobject in the scene,global illumination are destroyed.
so is there a way to recalculate GI when the game is running. I can’t find any API to do this in unity.
The job doesn’t need to real time. It can be like pressing the build button in unity editor.
But I don’t know how to implement it.Who can give me some advice.I would be very grateful.