Don't want people to jump? Then stick a one way shield under the wall they are on, and wazah, they cant jump and they have no clue why (I found this out today when my little bro was messing with forge, GOGOGOGO PHIL GO!)
Nice find! May be useful for puzzle maps and stuff like that. What way does the shield go, orange side up or down?
Indeed, you can also place it a good distance under the surface too so if you're floor has the stupid window detail bits (like 4x4) you can place it far enough down so you can't see the shield door at all.. Also, it's not really that relevant but if you mix 2 one way barriers together with both orange sides facing each other (but directly inside each other) and then do exactly the same 0.1 below the first pair, you can render all attributes of all 4 barriers useless... so it's like an orange shield door...
This works in reverse also. Place orange side up and set into a a ceiling. If you man cannon or jump to the ceiling voila...Anti-Grav Room!
i think you can also place it far enough under where vehicles arent affected by it. not sure how useful that is, but its worth saying.