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Revision as of 16:00, 26 September 2019 by Kidnation (talk | contribs) (Added specularcolor KV from Insurgency and DOI.)
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Light environment.png

light_environment is a point entity available in all Source games. It casts parallel directional lighting from the toolsskybox texture to approximate the light cast from the Sun or Moon.

Note.png Note: The properties of this entity apply to the whole map. Using more than 1 entity for areas with a skybox toolsskybox texture does not create errors provided If all instances of light_environment have identical info. It is pointless to have more than 1 though.
Tip.png Tip: Use with env_sun and shadow_control.
Note.png Note: The light_environment still inherits most properties from the basic light entity. This means that the light_environment can be named (by adding the targetname keyvalue with SmartEdit off) and even disabled/enabled, although it will look very crude as VRAD only calculates direct lighting for named lights.

Skybox lighting


Skybox Lighting enters the map through every toolsskybox-textured brush, representing direct sun/moonlight and diffuse skylight. Its basic properties are controlled by three entities used in combination (four in some games):

  • light_environment defines the direction, color and intensity of the direct sunlight, and the color and intensity of the diffuse skylight.
  • shadow_control defines the color, direction, and attenuation distance of the dynamic shadows that are created by light_environment. Dynamic shadows will be buggy and unconfigurable without this entity.
  • env_sun places a glowing sprite in the skybox to represent the Sun's apparent position in the sky.
  • env_cascade_light casts harsh, real-time shadows onto the map, usually copying settings from the light_environment entity. (only in Counter-Strike: Global OffensiveInsurgencyBlack Mesa (Source))

To make sense of it all, just make sure you have only one of each of these entities in your map, and that the Pitch and Yaw <angles> are set the same for all three of them. (Pitch is equivalent to the Sun's angle of elevation from the ground, and Yaw is its compass bearing.)

These lighting settings - direction, color, brightness, etc are fairly specific to the actual image used for the 2D skybox. The Sky List article suggests some settings for official game skyboxes. The worldspawn entity defines which skybox to use. Also note that fog will look wrong if env_fog_controller's settings don't correspond to the particular skybox in use.

Note.png Note: Pitch can be overriden for light_environment and env_sun, but not shadow_control. The Pitch override also cannot be switched off and its rotation is measured counter-clockwise from the horizontal (so straight down is -90°) whereas the <angles> Pitch's rotation is clockwise (so straight down is +90°). The workaround for this is to make sure your Pitch override merely repeats the <angles> value; for example, if your shadow_control, light_environment and env_sun <angles> are "45 -60 0", set the Pitch override to "-45".


Pitch (pitch) <angle>
Overrides the pitch value in Angles, even if left at 0, so it needs to be specified. Contrary to Angles, the rotation of this pitch is measured counter-clockwise from the horizontal, so that 90 is straight up, while -90 is straight down. (It's simply the negative of a normal pitch value.)
Brightness (_light) <color255 + int>
Color and brightness of the direct sunlight.
Ambient (_ambient) <color255 + int>
Color and brightness of the diffuse skylight.
BrightnessHDR (_lightHDR) <color255 + int>
Override for Brightness when compiling HDR lighting. Defaults to -1 -1 -1 1, which means "same as LDR".
BrightnessScaleHDR (_lightscaleHDR) <float>
Amount to scale the direct light by when compiling for HDR.
AmbientHDR (_ambientHDR) <color255 + int>
Override for Ambient when compiling HDR lighting. Defaults to -1 -1 -1 1, which means "same as LDR".
AmbientScaleHDR (_AmbientScaleHDR) <float>
Amount to scale the ambient light by when compiling for HDR.
SunSpreadAngle (SunSpreadAngle) <float> (in all games since Half-Life 2: Episode TwoHalf-Life 2: Episode Two)
The angular extent of the sun for casting soft shadows. Higher numbers are more diffuse. 5 is a good starting value. Remember: on cloudy days, the shadows will be blurred because the sunlight is being diffused by clouds. Try 90 for hazy days, and use 135 for cloudy days, rain and fog. If you're trying a night atmosphere, sometimes you'll need up to 180. You'll also have to turn down the shadow alpha in your shadow_control entity - try changing the Shadow Color variable to something such as 50 50 50.
Different SunSpreadAngle values. The quality of the soft shadows depend on compile options as well. Click to show animated preview.
Specular Color (specularcolor) <color255> (in all games since Insurgency)
Color of the light that reflects off of certain surfaces. (i.e. water).


Pitch Yaw Roll (Y Z X) (angles) <angle>
This entity's orientation in the world. Pitch is rotation around the Y axis, yaw is the rotation around the Z axis, roll is the rotation around the X axis.


  • 1 - Initially Dark - only works when the light_environment is named, and it must be added with SmartEdit off by putting in a 'spawnflags' key with a value of 1 as it is missing from Valve's FGD.

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