I noticed a huge slow down when painting grass on my terrain so I pulled up the Statistics and was surprised to see over 2000 calls and thousands VBO.
As I was erasing it I noticed the number drop dramatically.
So is each grass billboard an object?
In contrast, particles only use one or two calls for 1000s of them.
So if indeed each grass billboard is one object and it’s not a bug (and I would swear 2.01 didn’t eat up so many calls) how do I instead use particles ?
PS: how do I delete all the details from a terrain (and keep trees and heightmap) ?
Grass in the terrain engine can be of two types: either cross-section meshes, or camera-oriented billboards. Both types are grouped in patches, so it’s not one draw call per grass.
It’s dependent on the resolution of the detail objects in the terrain renderer and on the detail distance. You can tweak those values in the Terrain → Set Resolution menu item and in the terrain settings.
By default it is setup to have a sensible amount of draw calls / batch count. But of course if you tweak the numbers incorrectly you can easily hurt performance.
I sent the terrain via the Report problem menu in Unity, I’d really appreciate if you could take a look and inform us about those correct number you are hinting at.
By the way, what is target strength slider ? It acts as density but I couldn’t find documentation on this.
It increments by 6, so it’s either 0% or 6% which doesn’t offer finetuning for high res terrain.