light

light is a point entity available in all Source games. It creates an invisible, static light source that shines in all directions.

Warning: Naming a static light radically changes its behavior. See Naming Lights for details.

Keyvalues

Entity To Point At <targetname>

Entity to point this light at. Non-functional, as this entity casts light in all directions, all the time.

Maximum Distance <integer>

This is the distance that light is allowed to cast, in inches. Non-functional in Source 2013 later, use 50 and 0 percent falloff instead.

Light:

Brightness (_light) <color255 + int>

The RGB color and brightness of the light. Colors must be between 0 and 255; brightness can be anything.

BrightnessHDR (_lightHDR) <color255 + int>

Brightness override used in HDR mode. Default is -1 -1 -1 1, which means no change.

Warning: The fourth digit must be positive. Otherwise all light will be sucked out of your map!

BrightnessScaleHDR (_lightHDRscale) <float>

A simple intensity multiplier used when compiling HDR lighting.

Appearance (style) <choices>

Various Custom Appearance (see below) presets.

Custom Appearance (pattern) <string>

A string of characters, like a sequence of piano keys, that define a pattern of brightness. a is dark and z is full intensity. Applies only to lights with a targetname.

Constant (_constant_attn) <float>

Linear (_linear_attn) <float>

Quadratic (_quadratic_attn) <float>

These three values determine how the intensity of the emitted light falls off over distance. See Constant-Linear-Quadratic Falloff.

50 percent falloff distance (_fifty_percent_distance) <string>

0 percent falloff distance (_zero_percent_distance) <string>

Distances at which brightness should have fallen to 50% and (1/256)% respectively. Overrides Linear/Constant/Quadratic parameters if non-zero.

Bug: Using this setting will sometimes not work, which may or may not be related to using the light inside of an instance. Collapsing the instance and messing with the light's falloff values seems to help.

Hard falloff (_hardfalloff) <boolean>

Causes lights to fall to exactly zero beyond the 0% distance. May cause unrealistic lighting if not used carefully.

Cast entity shadows (_castentityshadow) <boolean> (New with Left 4 Dead) (Also in Garry's Mod)

Allows the light to modify the direction of nearby render-to-texture shadows so that they always point away from its origin. See also shadow_control.

Note:This keyvalue may not be available in some FGDs.

Shadow cast offset (_shadoworiginoffset) <vector> (New with Left 4 Dead)

A world-space offset that gets applied to the light origin when casting entity shadows. Useful for dealing with funny-looking shadows from very low lights: Just offset up the z axis. Default 0 0 0.

Note:This keyvalue may not be available in some FGDs.

Appearances

Literal Value	Description	Sequence	Preview
0	Normal	m
10	Fluorescent flicker	mmamammmmammamamaaamammma
2	Slow, strong pulse	abcdefghijklmnopqrstuvwxyzyxwvutsrqponmlkjihgfedcba
11	Slow pulse, noblack	abcdefghijklmnopqrrqponmlkjihgfedcba
5	Gentle pulse	jklmnopqrstuvwxyzyxwvutsrqponmlkj
1	Flicker A	mmnmmommommnonmmonqnmmo
6	Flicker B	nmonqnmomnmomomno
3	Candle A	mmmmmaaaaammmmmaaaaaabcdefgabcdefg
7	Candle B	mmmaaaabcdefgmmmmaaaammmaamm
8	Candle C	mmmaaammmaaammmabcdefaaaammmmabcdefmmmaaaa
4	Fast strobe	mamamamamama
9	Slow strobe	aaaaaaaazzzzzzzz
12 !FGD	Underwater light mutation	mmnnmmnnnmmnn

Targetname:

Name (targetname) <string>

The targetname that other entities refer to this entity by. Warning: Naming a static light radically changes its behavior. See Naming Lights for details.

Entity Scripts (vscripts) <scriptlist> (New with Left 4 Dead 2)

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 (thinkfunction) <string> (New with Left 4 Dead 2)

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.

Flags

• Initially Dark - only works when light has a targetname.

Inputs

TurnOn

Turn the light on.

TurnOff

The the light off.

Toggle

Toggle the light's current state.

SetPattern <string>

Set a custom pattern of light brightness for this light. If the Light is off, then this input appears to turn it on.

FadeToPattern <string>

Fades from first value in old pattern, to first value in the new given pattern. If the Light is off, then this input appears to turn it on.

Targetname:

Kill

Removes this entity and any entities parented to it from the world.

KillHierarchy

Functions the same as Kill, although this entity and any entities parented to it are killed on the same frame, being marginally faster than Kill.

AddOutput <string>

Evaluates a keyvalue/output on this entity. It can be potentially very dangerous, use with care.
Format: <key> <value>
Format: <output name> <targetname>:<inputname>:<parameter>:<delay>:<max times to fire, -1 means infinite>

FireUser1 to FireUser4

Fire the OnUser outputs; see User Inputs and Outputs.

Use  !FGD

Same as a player invoking +use; may not do anything. Can also be invoked by creating an output that does not specify an input.
This input is not included in Valve's FGDs.

RunScriptFile <script> (New with Left 4 Dead 2)

Execute a VScript file from disk, without file extension. The script contents are merged with the script scope of the receiving entity.

RunScriptCode <string> (New with Left 4 Dead 2)

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.

CallScriptFunction <string> (New with Left 4 Dead 2) !FGD

Execute a VScript function in the scope of the receiving entity.

SetLocalOrigin <coordinates> (New with Alien Swarm) !FGD

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.

SetLocalAngles <angles> (New with Alien Swarm) !FGD

Set this entity's angles.

Outputs

Targetname:

OnUser1 to OnUser4

These Outputs each fire in response to the firing of the like-numbered FireUser1 to FireUser4 Input; see User Inputs and Outputs.

OnKilled  (Only in the Left 4 Dead series)

This Output fires when the entity is killed and removed from the game.

See also

• light_spot
• Lighting
• Adding Light
• Intermediate Lighting
• Advanced Lighting
• Effect_flags (dynamic light effects)
• Tool textures (for Block light)
• $reflectivity (controlling reflected light off surfaces)