Copy lightmap info to foliage?

Hi all,

I had been trying to create a VR scene with baked workflow. Currently i am playing around with foliage and i couldn’t figure out the baking workflow for foliage.
I tried once and as i expected, it turned dark after light baking since there is only one side to the geometry.

Also, in some threads/comments I read we can copy lightmap data to foliage from the object below it. How can we do it?

Is there any proper workflow tutorial for foliage lightmass?

From a thread in forum