[Not a bug] [4.7.0pre-91] Portal Dynamic Light Bleeding

[Trusty McLegit]

Demo map included.
Using the built in dynamic lights on the lost souls you can see their lights in places they shouldn't be on the other end of the portals. This works with all dynamic lights so far as I can tell, making portals unusable with dynamic lights. Am I doing something wrong or is this a serious limitation?

[Rachael]

Yes they are supposed to do that but only with static portals and only with lights very close by to the portal linedef. Your portals are set up eternity style. If the lights move away from the portal linedef then they should eventually disappear.

This looks normal to me. When I summon torches far enough away from the linedef they do not appear on the other side, as expected.

If you don't want your portals to transmit lights, set them to interactive (type 2, not type 3). Static portals are meant for almost as convincingly as possible, to overlay one scene on top of another and patching them together.

[Trusty McLegit]

So for instance in this version, I want the torches cascading in through the archway towards the player. Instead almost all the light comes out the back. This is the intended behavior?

[Rachael]

Unfortunately, as wrong as that looks, yes, it is intended behavior. The torches are standing very near the portal line and therefore their light must be transmitted.

Again let me reiterate - static portals are meant to create a seamless transition from one area to another.

There is one issue though - and that is that the torches use the same shadowmap on both sides of the portal. It should not do this.

But beyond that - this is working as intended. Maybe not as intended on your part, but definitely as intended on the engine's.

[Trusty McLegit]

Okay, thank you for explaining.

[Rachael]

If you want to stop this from happening, make the portals type 2 (interactive) and not type 3 (static/eternity). Type 2 portals will not transmit lights. But they will not link an area together either for sound or sight checks. They will transmit hitscan attacks, i.e. bullet puffs though, and they'll move any movable object that crosses their line, i.e. monsters or missiles or players.