Grass Spawn doesn't work properly (unity 2021 - gaia 2021)

[Luneria]

Hello,

I'm creating a world for my 3D game, and since i'm using unity 2021.3.15f1 I bought Gaia 2021 (basic version). I have to say that on previous version of unity and gaia i hadn't any of this problem.

So, the problem is that when I spawn the grass, it spawns in lines as if the map was divided into 100 strips and there was only 1 out of 2 strips where the grass really spawned. And of course, i can't use a such world where the grass is spawned so weirdly.

Here is the settings :

 

Can you help me solve this strange problem please ?

 

If you also have some advice for the best setting I could set for the grass spawner, I would also be interested.

 

Thank you very much.

[Peter]

Hi @Luneria, if I'm not mistaken this could be a limitation in the Unity Engine when using the older non-instanced terrain details: Unity manages the terrain details in patches (or cells) on the terrain. You might have seen these settings on the terrain here:

The "Detail Resolution" is the resolution of the terrain detail spawning and determines how fine you can control the placement of grass and also how much grass is being displayed. The "Detail Resolution per Patch" signifies how large the patches or cells are that are rendered together. The larger the cells are, the more terrain details are rendered "in one go" and the better the performance, but there is also a limit on how many vertices can be displayed in a single patch at once. 
If the number of vertices in a single patch exceeds 65536, Unity will drop additional terrain details in that patch for rendering, meaning you will end up with terrain details missing on your terrain. This usually results in this line-like pattern that you are seeing, as only half of the patches are filled with terrain details.

In this case you have multiple options:

•  Decrease the "resolution per patch" setting on the terrain
• use meshes with less vertices
• reduce the spawn density
• look into using Unity's GPU instanced grass or Gaia's Flora system instead (both of which do not have this limit)

[Luneria]

Hello, thank you for your reply.

Indeed, I found out that there was too much details and that's why it couldn't spawn properly.

To resolve this, I reduced the spawn density and used GPU instanced grass and then it could work perfectly.

 

Have a great day 🙂

[Bryan]

Thank you for the update!