ok when i place a model in my map and i try it out i just walk trou it .... what to do?

u place a solid brush inside it ....

fx: u have a tree, u make a box (in hammer)
inside the tree, the texture of this box
shuld be somthing wooden
then u make it a func_wall and the set the render mode to texture and the FX amount to 0 thats it
hope u got it

i think this question should be put into the FAQ, because it is asked like every week.

why do all that instead of just drawing a box around it with the clip texture?

thats what i did and it worked fine

clip only blocks players, not bullets or ammo or dropped weapons or dropped objects, and it doesnt exhibit the proper particlefx, and it doesnt cast a shadow
thats why

ok thats wh yi asked ididnt know there was somethin better to do