I noticed a thread which requested an invisible wall, but had issues with placing in the editor as it cant be seen. I reckoned it could be done using LOD levels, so here it is
You have to change the distance for LOD_1 after placing these but it's not difficult and only needs to be done once,
after you finish placing all your walls in your game would be best. But you can switch it on and off at will if it suits you and your comfortable with it.
I am sure a way to draw these barriers will be introduced sometime but these may be handy for some just now who don't want a player having access to the entire map
Put the invisible wall folder into entitybank.
Press 'b' twice before starting to place these to snap them together, making it quicker and easier on yourself.
If you can't see the wall in editor you may have to scroll in a little for it to appear.
Instructions are included in the folder. Please make sure you read this before commenting that walls can still be seen in game
Required screenshot of invisible wall.
Personally I would simply swap out an opaque texture for a transparent one at build without messing around like this, but for those who don't know how to create these this may be of help for now. Still, being able to switch it on and off simply by changing distance for LOD_1 is kind of cool