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func_smokevolume is a brush entity available in all Source games.

Entity description

A brush entity that spawns smoke particles within its volume, commonly used for large, localised areas of fog. Use the trigger texture or the fog texture.

Warning: Smoke volumes should be used sparingly as they can decrease performance in heavily detailed scenes, or scenes with high amounts of action. Particle systems may be cheaper to use, depending on CPU usage restraints.

Warning: Smoke volumes shouldn't be placed in the same volume as func_precipitation is. Otherwise engine may freeze at the end of loading the level. It is probably caused by some particle coding that do not accept this two types of sprites to render at once (in the same volume).

Note:The default material is particle/smoke_grenade1, which does not exist. However, particle/particle_smokegrenade does.


Particle Color1 (R G B) <color255>
How dim particles can be.
Particle Color2 (R G B) <color255>
How bright particles can be.
Note:Darker particle colors will appear nearly invisible without being close to a bright light source.
Material <material>
The material to use for the particles
Particle Draw Width (units) <float>
The size of the particles, in units/inches. (Typical Values: 128,175,200,500,512)
Particle Spacing Distance (units) <float>
The distance between the particles inside the volume. The lower the number, the denser the particles, and the more overdraw there will be. It is best to keep it as high as you can without it looking bad. (Typical Values: 125,150,200 and sometimes 80 or 480)
Density Ramp Speed (seconds) <float>
Time to go from density 0 to density 1, in seconds.
Rotation Speed (degrees/sec) <float>
The speed that the particles should rotate, in degrees per second. (Typical Values: 3,10)
Movement Speed (units/sec) <float>
The speed that the particles should move around, in units/inches per second.
Density [0..1] <float>
Particle density, from 0 to 1. (Typical Values: .1-.5)


Name <string>
The targetname that other entities refer to this entity by.
Entity Scripts <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 <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.


  • 1 : Emissive
Makes sprites render fullbright. Normally the brightness is affected by light nearby.


SetRotationSpeed  <float>
Set the particle rotation speed (in degrees per second).
SetMovementSpeed  <float>
Set the particle movement speed (in inches per second).
SetDensity  <float>
Set the particle density. It should be a range from 0 to 1.


Removes this entity and any entities parented to it from the world.
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 <Left 4 Dead 2>, 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.



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.