So you want an area to be visible but you dont want peeps getting
there? or you want a invisible wall? could the invisible man walk
through an invisible wall?
anyway, just select the aaa texture and make a block where you
want to block people from getting to. now select tie to entity,
and then select func_wall, now in the renderfx, select solid,
and in the x amount leave that at 0. I think this blocking method
is best for preventing players from reaching somewhere they dont
want to be going, like on a roof for instance. Not blocking certain
places can make your map unplayable and spoiled, because there
are always players wanting to get to interesting places, trying
to exploit your map :P so dont let your hard work go to waste,
and block um.
you have your invisible wall, watch out for the invisible man,
or should I say hollow man?
you can also make a block and apply the clip texture to it and
this will block player movement, but not bullets or grenades(you
do not have to make it an entity it will show up in map invisible).If
your map is big and running short on clipnodes this could also