https://player.vimeo.com/video/689315739?h=1f3a96ec00&badge=0&autopause=0&player_id=0&app_id=58479
Clicking this tick box will activate the Camera FOV (Field of View) option, but you will see no impact until you reference a camera in the Camera link field, below.
Simply drag and drop your scene camera into this link field to see grass being generated, but only in the camera’s field of view.
The grass will automatically cut off in the defined field of view, but you can add more generation to this edge point by raising this percentage slider.
The camera’s field of view with a Padding value of 0 (zero) %.
The camera’s field of view with a Padding setting of 60%.