how to make the grass like in serious sam

i have bin playing serious sam and like wow that engine has a lot of grass plants and trees in one shoot how can this be done having that mutch grass

not sure.. (I don't have serious sam) hoewever, the classic way is to use a bunch of quads with transparency.

Because they aren't drawing every blade. They have a grass texture that they slap onto a mesh with a couple of intersecting polygons in it. Repeat that mesh a few times and voila, grass.

The Grass Demo by Adam Gore is almost like the
serious sam gras and the sun too, check out
that code maybe its what youre looking for..

There's a very good single surface grass thingy in the archives by jfk and masterbeaker.

http://www.blitzbasic.com/codearcs/codearcs.php?code=807

Hope that helps some :)