Just a minor one. I don’t know if this affects any other vents/grates, but this one doesn’t have collision for physics objects (tested with a HEV battery and a headcrab ragdoll).
map : bm_c1a2a at: -46 x, 808 y, 49 z
Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.