Hello, I would like to do "Straight Grass on Slopes tip"

Hello,
I would like to do “Straight Grass on Slopes tip” that wee can see in "From Ants To Outer Space | Indside Unreal at 47:00 (From Ants To Outer Space | Inside Unreal - YouTube).

It’s not that complicated but i don’t know how to squeezed flat the vertices of the grass mesh and still get the height with the vertex color.

Thanks in advance if you can respond !

Wish you an Happy New Year

:smiley: