In a map I am currently making, I have grates. I need funnels to be able to go through the grates as part of my map. To do this, I simply tied the grate to a func_brush and turned off its solidity, then placed a clip brush around it.

However, this brings up a new problem, and that is that physics objects can fall right through the grate (clip brushes to not affect physics objects in Portal 2). So, my question is, how do I make a physics-object clip of some kind? I know it's possible (read: green grills in Retrospective); I'm just not sure how.

EDIT: I can't spell.
EDIT 2: I still can't spell. Also, solved.

Func_clip_vphysics. Boom.

Hope it works.

Indeed it does! Viel Danke.