Volumetric grass

I've been extremely interested in volumetric technology. Especially in volumetric grass.




The online resources are extremely scarce on this topic.

What is the difference from creating a lot of mesh billboards?
Is this shader based technology or simply geometry type of generator?
Do you have any pointers or resources where to start to be able to create something like this?

Any hints much appreciated.

 

Volumetric grass is shader based and much more performant than billboard meshes. How much do you know about shader?
I guess if you are good enough with shaders, you will find your own solutions. If not, there is a volumetric grass asset on the asset store.

 

It's not always higher performance. Billboards esp with cutout can outperform a heavier volumetric pixel shader approach. I'm not sure why misinformation?

 

Because those are very very edgy cases? You would need a very fast cutout shader with batching and compare it with a very heavy volumetric grass shader to get even close results. With standard billboard meshes the overhead of the gameobjects would be too high, with batched meshes culling gets problematic.

An empty terrain with 60 meters detail distance gets drawn with 140 fps, whereas several kilometers of a shader could be rendered with 950 fps.

I tried that just a few days ago and came to the conclusion that shadergrass is fast, but not editable enough, unity grass meshes on terrain look better, but are slower and speedtree grasses as a tree asset are slow as hell and look the worst