One way viewpoint door possible in code?

[mindfane]

@Shambler;128891

I did this in UE2 by using the stencil buffer to draw the portal over the main scene, and I think that is the standard way of doing this no matter what the engine is - given how heavily the stencil buffer is used by the engine though, in both UE3 and UE4, doing this would probably require expert knowledge of the internal rendering system, and a lot of customization, in order to make it work.

Disclaimer: I know next to nothing about working with the rendering system though this would make for a lengthy/fun and highly educational project.

Yes thats the most efficient way to do it (as far as I know). However the physics is still a problem. If you only need to allow the player to go through such a door, then a teleportation could do it. But if you need physical objects to respect this door (like portal), then things are much more difficult.

I had some success in recreating the visual effect of a portal using just blueprints. Here is the demo and scene setup

Portals using UE4 Blueprint : Gameplay Demo

Scene setup: https://www.youtube.com/watch?v=o9TNOUiNjpI
However it has a heavy hit on performance and a 1 frame delay whcih is very noticeable. I did not work on it much (I did that in less than 2 hours) and never touched it gain.