The Emit Entity

The *misc_emit* entity is a client-sided entity type used to enrich your levels with non-vital information such as static models, particle torches, flickering lights, and ambient sounds. This entity is highly customizable based on several key-value pairs.

Similar to *Quake 2*’s *spawnflags* key-value pair, a set of *flags* exists for enabling certain *misc_emit* features. Whenever possible, these are automatically resolved by the game engine based on the key-value pairs you have set on the entity. Still, you will sometimes need to add these values to the *flags* key-value pair manually.

EMIT_LIGHT 1
EMIT_SPARKS 2
EMIT_STEAM 4
EMIT_FLAME 8
EMIT_CORONA 16
EMIT_SOUND 32
EMIT_MODEL 64

flags
: A bit-masked integer value; see above. When possible, flags are automatically resolved by the game engine based on the presence of other key-value pairs described below. However, some flag values must manually be set.

angles
: 3 positive floating point values in degrees, these provide directional information. Applicable to `EMIT_SPARKS EMIT_MODEL`.

color
: 3 positive floating point values, these provide rgb color information. Applicable to `EMIT_LIGHT EMIT_CORONA`.

count
: A positive integer value which provides particle count information. Applicable to `EMIT_SPARKS`. Default is `12`.

drift
: A positive floating point value which provides some variance to event frequency. Values greater than `0.0` and smaller than `5.0` are most useful. Applicable to `EMIT_LIGHT EMIT_SPARKS EMIT_STEAM EMIT_FLAME EMIT_SOUND`. Default is `0.01`.

hz
: A positive floating point value which provides an event frequency baseline. Applicable to `EMIT_LIGHT EMIT_SPARKS EMIT_STEAM EMIT_FLAME EMIT_SOUND`. Use the `drift` key to add variance. Sane defaults are used where possible.

model
: The game path of a model file, e.g. `outpost/tree`. The model must be a static mesh (i.e. not animated). It will be positioned according to the angles key. Applicable only to `EMIT_MODEL`, which is set when this key is present.

radius
: A single floating point value which provides radius information. Applicable to `EMIT_LIGHT EMIT_CORONA EMIT_FLAME`. Defaults are `1.5`, `12.0` and `1.0` respectively.

sound
: The game path of a sound sample, e.g. `aghast/drip`. When no `hz` value is provided to emits which have a sound key, they are treated as looped ambient sounds. Applicable only to `EMIT_SOUND`, which is set when this key is present.

velocity
: 3 floating point values in units, these provide directional velocity information. Applicable to `EMIT_STEAM`

attenuation
: Determines the size of the area in which a given sound is heard. Default is 1. Lower values will increase the range of the sound, whereas higher values will make the sound more localized. Setting this to -1 will make a sound play globally. Applicable to `EMIT_SOUND`

Examples
—-
A torch flame, automatically accompanied by a crackling fire sound effect:

{
// entity 1
“classname” “misc_emit”
“origin” “-24 512 256”
“flags” “8”
}

An ambient drip:

{
// entity 2
“classname” “misc_emit”
“origin” “786 1284 16”
“sound” “aghast/drip”
}

A flickering light with sparks:

{
// entity 3
“classname” “misc_emit”
“origin” “-224 640 -64”
“angles” “0 270 0”
“flags” “3”
“color” “1.0 0.9 0.5”
“radius” “1.25”
“count” “20”
“hz” “0.25”
“drift” “0.5”
}

A steam emitter, pointing downward and slightly north-east, and automatically accompanied by a hissing sound effect:

{
// entity 4
“classname” “misc_emit”
“origin” “216 -48 512”
“flags” “4”
“velocity” “10 10 -40”
}

A static mesh tree:

{
// entity 5
“classname” “misc_emit”
“origin” “-1024 -42 168”
“model” “outpost/tree”
“angles” “4 270 0”
}