Weird Black lines on landscape material

[AngusMiso]

Hi there , i have a problem about painting on the landscape ,
as the picture shown , there are some random weird lines popping up on the landscape i painted.

the only solution i know is to sculpt the landscape a little bit until all the line disappear , but the landscape is huge and hard to find out where i missed ,
and the terrain will be messed after this way.

does anyone know the reason and how to figure this problem ??
really need help , thanks alot

[AngusMiso]

@MostHost LA

It may be a tessellation crack but it doesn’t look like it.

Using the landscape tools removes it, so it should be tessellation.

You can try removing tessellation from the terrain material and waiting to see if after compiling the lines are gone. that’ll get you to eliminate that as the issue and we can try something else…

Thanks , but my landscape material didn’t turn the tessellation on.
still trying on the material’s prop D: