Grass: To Billboard or Not to Billboard

So I've been going through a myriad of games just to look and see how their grass/details are being implemented and I've noticed that some of the best looking grass out there doesn't seem to be billboard, but rather a fairly dense crossing pattern of regular 2D images that when you move around the grass it seems to always have a large cross-section facing you and hence can take on the appearance of a 3D object. I don't think they are objects or prefabs per se because I can stand directly over them and see they are 2D in nature.

So here's the questions. Am I right in guessing these are just dense packs of 2D images randomly faced to produce this effect? If it's not this, can someone tell me what it is? And aside from the obvious difference in imaging can anyone tell me how much of a performance issue is it(obviously taking into consideration same resolution images)?

Thanks in advance for the info.

 

I've not yet found myself working with grass, but when I do I want to give this a shot.

https://forum.unity.com/threads/bes...s-runs-as-fast-and-looks-just-as-good.339792/

Additionally, Game Design is typically used for more theoretical discussion. Only saying this because you haven't gotten any replies. You might have had better luck elsewhere, such as the Graphics sub-forum.

 

I wondered about that but the Graphics forums didn't have questions like this either....oh well. Thanks for the link though, that does look interesting.

Edit: Did the full read through, looks like at one point this wasn't possible anymore, but so far it's looking good.

 

What do you think billboards are?