How to allow the player to go through worldspawn at a particular spot?

[typedef state]

I'm thinking of implementing a system similiar to the world portals of Portal 2, where there is an area in the world that connects with another area in the world, both visually and physically. I'm thinking how should I go about disabling collisions for the player where he should collide with the environment? Has anyone done this before? Does anyone have any thoughts?

Basically, how to make the player not collide with a certain part of the map?

Thanks in advance.

[Rubat]

You can't do that without recoding the entire movement system in Lua as far as I know. Maybe you can do some hacking with noclip, but that's never a good solution.

I know MDave successfully did that, but I do not know if he ever finished it.