Anyway... I checked the road map again and now I think, that at least some of the grass is done via the material texture. If I check the road textures, it's true and there are grass sprites randomly spawned on them.
So, I am using this in my map right now. But - and to finally come to my problem - there is a problem. The range is not wide enough. It pops up like 5 meters in front of me and in the distance it's faded out and not visible (like it should be). First I thought its always like that (the short range - which would be bad) but then I checked the road map ingame again and saw that it is poping up there too, but in a much wider range.
My question now would be... is it somehow possible to change the "popup range" of the sprites? I checked already the valve dev wiki and some other sources, but I am totally out of ideas.
Maybe the mapper of the original map could enlighten me? Or someone else with some more experience in this than me?

