Yeah, I dont suggest using sprites for grass (sprites are best used for symmetrical things, like spheres. ex: env_glow). If you walk on top of them, and look down.. you get a pathetic view of the grass (try it out for yourself if you dont know what I mean) Models are definately nice (check out de_airstrip for a good example of model plants. I agree with Cap'n, the triangle method gets messy after a while. Also, most HL maps dont go overboard with the terrain, it is just unnatural to have extremely uneven terrain, you can make a subtle difference, but the product isnt worth the r_speeds it can produce.