A question about the limitation of terrain layers

[skyfam2]

Unity - Manual: Terrain Layers

I dont understand this part:

you can use four Terrain Layers per Texture pass, with no limit on the number of passes. This means that although you are allowed to use as many Terrain Layers as you want, each pass increases the time spent rendering the Terrain. For maximum performance, limit each of your Terrain tiles to four Terrain Layers.

what does the “texture pass” mean? is it “the neighbor terrain”?If I want to paint more than 4 layers,I have to add more neighbor terrains and paint there ?

[Ruslank100]

You can paint more than 4 layers at the same terrain
However Unity can render the terrain in 4 layer batches. If you have more than 4 textures on a single terrain Unity will have to repeat the render process again, meaning the render time for the terrain will increase

[nasos_333]

@Ruslank100

You can paint more than 4 layers at the same terrain
However Unity can render the terrain in 4 layer batches. If you have more than 4 textures on a single terrain Unity will have to repeat the render process again, meaning the render time for the terrain will increase

Hi

Is there a way to limit the passes unity uses if using a single pass shader but have more than one pass textures active ?