light_dynamic

light_dynamic is a point entity available in all Source games.

Class hierarchy
CDynamicLight ↳CBaseEntity
dynamiclight.cpp

It is an invisible light source that changes over time, casting dlights on brushes and elights on models. Can be turned on and off through inputs, and can aim at any object, including moving ones. Dynamic lights are calculated on the fly in the game, which means they have a higher processing cost but are much more flexible than static lighting. It is also the only entity except env_projectedtexture that can light up brushes in real-time (but it doesn't replace their original lighting).

An example Light_dynamic with different colors

Note:This entity actually consists of two lights, a cone model light and a spot brush/displacement light. Some values may affect one and not the other.

Note:For the light to work properly, the "Maximum distance" keyvalue must be greater than the distance from the entity to the surface it is supposed to light, otherwise it will not show. Also, it is recommended to set the "Light brightness" keyvalue to either 6 or 8 as it typically looks best. Normal brightness values do not apply. Finally, adjusting the angle using the circle tool in the top-right or by using the "point at" tool will only adjust the cone model, the angle keyvalue must be set manually to adjust the spot world light.

Note:For the 2013 SDK this is limited to 32 lights on at any one time so use wisely.

Note:For spotlights, it is recommended to use env_projectedtexture for more realistic and accurate dynamic lighting.

Warning:Both dlight and elight can't shine throught portals in Portal and Portal 2.

Warning:This entity reduces performance, especially with small luxel scale for lightmaps and custom appearance. For example, in Black Mesa (mod) sentry turrets are causing 30-40 frame rate drops in some areas.

Important: Xengine uses deferred lighting for this entity. Console commands (see below) and spawnflags do not work, unique inputs are also removed. Used for entities from Dynlightscript.txt. Use newLight_Point for omnidirectional dynamic lights in this engine branch.

Bug:In Xengine, you can use omnidirectional light only, spot light is broken. Always use 0 value for Outer (fading) angle property for this entity. If you need dynamic spot light, use newLight_Spot entity. The bug example.

Limitations

Example with static and dynamic prop.

• This entity can't cast any shadows, which means it will shine thought world geometry, etc.
• There is no filtering for such lights, which is why they look like stairs in comparison with baked light sources, especially on brushes with a high value for luxels.
• No falloff settings.
• Static props are not lit properly, even if per-vertex lighting is disabled.

Keyvalues

Name (targetname) <string>[ Edit ]

The name that other entities refer to this entity by, via Inputs/Outputs or other keyvalues (e.g. parentname or target).
Also displayed in Hammer's 2D views and Entity Report.

See also:  Generic Keyvalues, Inputs and Outputs available to all entities

Entity to point at (target) <targetname>

The name of an entity in the map that the dynamic light will point at.

Light color (_light) <color255>

The RGB render color of the spotlight. Colors must be between 0 and 255.

Light brightness (brightness) <integer>

The intensity of the spotlight. Maximum 127.
Negative numbers, while parsed as valid down to -127, do not seem to do anything.

Inner (bright) angle (_inner_cone) <integer>

The angles of the inner spotlight beam. 0 makes it omnidirectional.

Outer (fading) angle (_cone) <integer>

The angles of the outer spotlight beam. 0 makes it omnidirectional.

Pitch (pitch) <integer>

Used instead of Pitch Yaw Roll's value for reasons unknown.

Maximum distance (distance) <float>

This is the distance that light is allowed to cast, in inches.

Spotlight end radius (spotlight_radius) <float>

This is the radius of the light, in inches, at the object that it is hitting.

Appearance (style) <choices>

Various lightstyle presets.

Lightstyle presets (epilepsy warning) Expand

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	Underwater light mutation	mmnnmmnnnmmnn

Note:Custom lightstyles are not supported.

Flags

Do not light world (better perf) : [1]

Prevents this entity from creating a dlight.

Do not light models : [2]

Prevents this entity from creating an elight.

Add Displacement Alpha : [4]

Bug:If enable - light source will be invisible in Black Mesa.

Subtract Displacement Alpha : [8]

Inputs

Color <color255RedirectInput/color32>

Set the light's render color (R G B).

Note:The only input that exists in Black Mesa version, although doesn't work.

brightness <integerRedirectInput/integer>

Set the light brightness. It may take time for the brightness to update.

distance <floatRedirectInput/float>

Set the maximum light distance.

_inner_cone <integerRedirectInput/integer>

Set the inner (bright) angle.

_cone <integerRedirectInput/integer>

Set the outer (fading) angle.

spotlight_radius <floatRedirectInput/float>

Set the radius of the spotlight at the end point.

style <integerRedirectInput/integer>

Change the lightstyle (see Appearance field for possible values).

TurnOn

Turn the light off.

TurnOff

Turn the light on.

Toggle

Toggle the light on/off.

Dedicated ConVars

Cvar/Command	Parameters or default value	Descriptor	Effect
r_dynamic	1	Bool	Enable/disable dlight rendering, doesn't affect elight.
r_dynamiclighting	1	Bool	Enable/disable dlight updating, doesn't affect elight.
r_maxdlights	32	Integer	Sets the maximum amount of dynamic lights.
r_portal_use_dlights (only in Portal 2)	0	Bool	Enable/disable dynamic lights from portals.

See also

• Light_deferred
• Lighting
• newLight_Point
• newLight_Spot
• Light entities