light_environment
light_environment is a point entity available in all 
GoldSrc games.
Description
Creates the sunlight emitted from sky brushes. There needs to be one per PVS if using the default compile tools. Only one is needed per map if using the ZHLT compile tools.
Key values
- 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
<color255 + int> - Color and brightness of direct Sunlight.
Targetname:
- Name
(targetname)<string> - The targetname that other entities refer to this entity by.
- 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.
ZHLT light source:
- 0 : Default
- 1 : Inverse Linear
- 2 : Inverse Square
- Texlight (VHLT+)
(_tex)<texture> - HLCSG will rename this entity to light_surface, using the specified texture as the emissive texture.
- Ambient (ZHLT+)
(_diffuse_light)<color255 + int> - Ambient 2 (ZHLT+)
(_diffuse_light2)<color255 + int> - Sun spread angle
(_spread)<integer> - Model lighting only (VHLT v16+)
(_fake)<boolean> - Treat this entity as an info_sunlight, causing it to not affect lightmaps.
