Bloom Restoration (VScript Overlay)

This mod adds a custom pixel shader to restore the bloom effect, activated via "screenspace_general" material shader and "env_screenoverlay" entity with VScript.

If you want this mod to work client-side without VScript (meaning, play with the mod on any server), consider giving (https://steamcommunity.com/sharedfiles/filedetails/?id=3659480578) a try.

Background:

The bloom effect was present in Left 4 Dead 1 from the start of 2007 (or possibly even earlier) up until a major redesign in the middle of 2008, when local contrast and other horror-film post-processing techniques were introduced. The likely reason why the bloom didn't make it to the final game was the fact that the new post-processing effects coupled with bloom caused a huge overdraw and put an additional strain on the hardware. That, or the artists at Valve thought that the bloom didn't fit the new art direction and decided to remove it. Possibly both.

Personally, I've always loved how bright and bloomy Source Engine games looked since HDR was introduced in Lost Coast. So here's my attempt to restore that iconic bloom effect and see it rise and shine once again in Left 4 Dead too. The shader itself isn't an exact replica of the original, but it looks decent considering the current implementation restrictions.

Notes:

• Since the mod is implemented through VScript, you need to host a local server to see its effects (other players in your lobby will also see the mod's effects if they have it installed, otherwise, the bloom won't be visible for them).

• Will conflict with other screen overlay mods if they also use "env_screenoverlay" entity (barely any mods use it though, most of them are implemented as a HUD element).

• Doesn't interfere with the game's UI, sprites, post-processing effects and on-screen particles (such as adrenaline, blood splatter, boomer vomit, etc).

• Bloom intensity, threshold and size are configurable inside simple_bloom.vmt material (you'll have to unpack the mod's .vpk addon if you want to edit it though).

• Expect a performance hit on a low-end PC.

Special thanks:

jackdavenport — original GLSL bloom shader I used as a base ficool2 — making the SDK and a helpful guide on how to create and implement custom pixel shaders into games built on Source Engine