This entity controls a bunch of cinematic post-processing effects primarily used in the Left 4 Dead series. Many of the effects were designed specifically to supplement Left 4 Dead's "filmic" art direction, such as film grain or local contrast.
Multiple controllers can exist in the map at the same time and each controller be applied on a player-by-player basis, with effects fading between each other automatically. A
postprocess_controller can be enabled on a player by using the
SetPostProcessController input, the "Master" spawnflag, or the
fog_volumein the map in order for a master
postprocess_controllerto take effect.
Film grain heightens the frightening feeling of dark and shadowy environments. This helps make the cinematic experience as gritty and authentic as possible and effectively implies a greater detail to the surrounding darkness than is actually there. The technique avoids applying film grain uniformly as it causes players to get tired of it fast. Instead, film grain is prevalent in very dark areas with lots of shadows. The brighter an area gets, the more the grain fades into the background, causing it to disappear entirely in very bright areas.
Vignetting is a lens artifact you'll often see in lower budget films where cheap cameras were used: specifically, dark edges seeping in around the edges of the screen. Even still, it usually needs to be applied sparingly. As shown in the example picture, the effect was only applied around all of the top edges of the screen, so a player wouldn't feel like they were looking through a telescope. A little goes a long way — playtesters don't feel like it intrudes their view at all. It also does a good job of softening the top edges, focusing the gameplay downwards to the center of the screen, where you want a player to look.
Local contrast is a technique borrowed from photo retouching, where the contrast is adjusted specifically on areas of an image that contain a high level of visual detail. This technique helps make the visuals sharper and more focused. It is a convenient way to effectively imitate the feeling of an adrenaline rush or near-death experience. The effect gives the player a sense of heightened perspective, and is a great subliminal way to foreshadow imminent danger.
Depth and full screen blur
Depth and full screen blur apply a blurring effect to certain parts of the screen. Depth blur allows blur to be applied at a certain focal distance and screen blur applies the effect across the whole screen.
To do: Example picture and full explanation.
Fade out/Fade to black
"Fade to black" simply fades the screen into complete darkness. Normally,
env_fade (which provides more control over the fade's properties) would be used for fading the screen, but some post-processing effects are still applied or do not disappear smoothly when
env_fade is used. The "Fade to black" effect is applied after all of the other effects, allowing them to fade with the rest of the screen. This is recommended if the other effects controlled by this entity are used often and should not appear in intro/outro fades.
- Fade-in time
- Fade-in time
- Local contrast strength [-1..x]
- Local contrast strength
- Local contrast edge strength [0..1]
- Local contrast edge strength
- Vignette start distance [0..1]
- Vignette start distance
- Vignette end distance [0..x]
- Vignette end distance
- Vignette blur strength [0..1]
- Vignette blur strength
- Fade to black strength [0..1]
- Fade to black strength
- Film grain strength [0..x]
- Film grain strength
- Top-of-screen vignette strength [0..1]
- Top-of-screen vignette strength
- Depth-blur focal plane distance [0..1]
- Depth-blur focal plane distance (in dest alpha space [0,1], not world units)
- Depth-blur effect strength [0..x]
- Depth-blur effect strength
- Full-screen blur strength [0..1]
- Full-screen blur strength
- Entity Scripts
- Space delimited list of VScript files (without file extension) that are executed after all entities have spawned. The scripts are all executed in the same script scope, later ones overwriting any identical variables and functions.
- Script think function
- Name of a function in this entity's script which will be called automatically every 100 milliseconds (ten times a second) for the duration of the script. It can be used to create timers or to simulate autonomous behavior. The return value (if present) will set the time until the next call. Note: Try to avoid expensive operations in this function, as it may cause performance problems.
1] : Master
- Has priority if multiple postprocess_controllers exist
- Set the local contrast strength.
- Set the local contrast strength at the edge of the screen (controlled by vignette).
- Set the vignette start distance (from screen center).
- Set the vignette end distance.
- Set the strength of the desaturated blur on the vignette.
- Set the fadeout strength.
- Set the focal distance of the depth blur effect (in dest alpha space [0,1], not world units).
- Set the depth blur effect strength.
- Set the screen blur effect strength.
- Set the film grain effect strength.
- Set the fade time between post process settings.
- Removes this entity from the world.
- Removes this entity and its children from the world. Note: Entities already remove orphaned children upon being removed, but this input removes all children on the same frame, being marginally faster than
- Adds a keyvalue/output to this entity. It can be potentially very dangerous, use with care.
<output name> <targetname>:<inputname>:<parameter>:<delay>:<max times to fire, -1 means infinite>
- Fire the
OnUseroutputs; see User Inputs and Outputs.
- Same as a player invoking +use; may not do anything depending on the entity. Can also be invoked by firing an output that does not specify an input.
- Execute a VScript file from disk, without file extension. The script contents are merged with the script scope of the receiving entity.
- Execute a string of VScript source code in the scope of the entity receiving the input. String quotation may be needed when fired via console. Bug: In , the code is executed in the script scope of the entity that fires the output, not the one receiving the input.Warning: Never try to pass string parameters to a script function with this input. It will corrupt the VMF structure because of the nested quotation marks, which then must be removed manually with a text editor.
- Execute a VScript function in the scope of the receiving entity.
- Send this entity to a spot in the map. If the entity is parented to something, it will be offset from the parent by this amount.
- Set this entity's angles.
- These outputs each fire in response to the firing of the like-numbered
FireUser4Input; see User Inputs and Outputs.
- This output fires when the entity is killed and removed from the game.
L4D Art Direction, Part 1: Filmic Effects - Valve blog regarding film effects in Left 4 Dead