So i have a platforming puzzle, more like combat on small catwalks, and I want to prevent the player from shortcutting at a small junction. After they get to the end however i have no problems with them jumping down, through, or across.

Naturally I did some homework and found that collision layers were an easy thing to install. But is there a way to make it one way blocked and the other have no resistance?

I figure i could have triggers to enable to disable but that seems more complex than just altering the puzzle or seeing if there was such a thing as a one sided collision layer.

Don't know anything about one-way collision. I suggest you simply disable it when player enters trigger. Nothing complex here. There should be a default script for this, so you don't even need creating a new one.

Rather simple. There are already one-way collision meshes in the game. For instance: wrintfloordirtmid01.nif

Edit it and give it a new ID, then check "is marker"

https://picasaweb.google.com/lh/photo/3eQ45DQCxaNgkv1ZZMiJGNMTjNZETYmyPJy0liipFm0?feat=directlink

and rotate it to your liking. The piece will be visible in the CK (as long as you did not untick the M for markers) but will be invisible in the game.

You can walk through from the untextured side but not from the other side.

You can make any objet a marker so it will be visible only in CK? Cool, didn't know that. Also, you mean that markers still have meshes, but don't have textures?

About collision: maybe I'm wrond again, but I'd still suggest using trigger and Disable() to do that. I'm not sure that one-way collision always works fine. It hasn't ever been used in default game.

This is an original mesh with textures that are set invisible by the "is marker" flag.

Why should the collision/no collision not work? I tested it out in my test file without problems.

It works fine.

I used this method once when an exit to a dungeon was hidden by a waterfall. I didn't want anybody stumbling upon the exit, so I put this type of collision in the waterfall. You could stll exit OK, but you could not enter.