Hey all,
Is there any way (through script or setting somewhere) to make the detail texture billboards either hide or flatten when a collider/rigidbody is on top of them? The whole grass pop-through thing doesn’t exactly look great xP
as they don’t collide, no. you will have to do them through an own system instead of the terrain painting
There’s no way to access that data from scripts? 
there is no data
detail objects are placed basing on a density map, they don’t exist in any mesh form thats accessable neither through documented nor undocumented api.
you could manipulate the density map in realtime, though. Replacing the grass prototypes with a different one, or removing it. From my experience, however, that is not useful for objects rolling through the grass or such, as the performance impact is considerable. If you only need it every once in a while, it could work.
You will have to go by position, as there are no colliders on detail or grass.
the problem with that replacement is that there is no guarantee that it affects the gras you really touch .at worst not even gras close to you. messing with the density when I remember right would even update all gras in that pixels influence at very least … good luck explaining that while you are standing in a patch of gras 
Well, I’ve solved the visual issue by putting a lot looott more grass down, and lowered the draw range. This stops the pop-through grass effect that I wanted to get rid of, but isn’t exactly what I wanted. Good enough, though. Thanks all!