`env_flare` incompatible with portals

[MyGamepedia]

Describe the bug

1. env_flare particles incorrect work with portals. env_flare use particles that incorrect work with portals, this particles also use props that use in physgun_interactions function create_flare (Half Life 2: Episode 1 flare for example). It looks like this particles fully connected to player screen. Here I show that it's not visible through portals if player screen not see it.

https://github.com/StrataSource/Portal-2-Community-Edition/assets/103366204/eadd424d-7384-45c8-9d81-e448ad3b0efb

Here I show that if player see it - it'll render in portals and not hiding if objects in portal hide it, but it's hiding if player screen not see it.

https://github.com/StrataSource/Portal-2-Community-Edition/assets/103366204/638734d1-6680-49fe-8a55-61081ab371de

This problems also in Portal and should work in Portal 2.

2. env_flare flare never go through portals. You can find it in some Half Life 2 and episodes maps. This also in Portal.

https://github.com/StrataSource/Portal-2-Community-Edition/assets/103366204/deaa5ea8-11fe-497a-9d0d-00c93d963af8

Issue Map

Any.

To Reproduce

1.1. Open any map. 1.2. Enter in console sv_cheats 1; ent_create env_flare; impulse 101; ent_create_portal_companion_cube. 1.3 Experiment like in the videos. 2.1. Open my map for quick test. flare_test.zip 2.2. Place portal under env_flare. 2.3. Press button to launch it. 2.4. Pay attention that it's don't go through portals.

Operating System

Any.

[vrad-exe]

Slightly off topic but please put this in p2ce/scripts so all of the HL2 sounds in your videos aren't fiddlesticks

game_sounds_manifest.txt

[MyGamepedia]

Slightly off topic but please put this in p2ce/scripts so all of the HL2 sounds in your videos aren't fiddlesticks

game_sounds_manifest.txt

I most often disable sounds, but thank you!!!