Wiki: light

light - Point Entity

Point-based light. It can also be toggled on/off and pulse in a variety of pre-defined styles (as well as custom ones) in a limited fashion.

Target (target) - When an entity is activated, it triggers the entity with the name specified by Target.
Name (targetname) - Property used to identify entities.
Brightness (_light) - First three 3-digit numbers are the color (RGB). The fourth number is the brightness. e.g. 255 0 0 300 will produce a red light with a brightness of 300 units.
Appearance (style) - Light appearance. Values:
- 0 = Normal
- 1 = Flicker A
- 2 = Slow strong pulse
- 3 = Candle A
- 4 = Fast strobe
- 5 = Gentle pulse
- 6 = Flicker B
- 7 = Candle B
- 8 = Candle C
- 9 = Slow strobe
- 10 = Fluorescent flicker
- 11 = Slow pulse, no black
Custom Appearance (pattern) - Use a string of letters to provide a custom light style (see note).
ZHLT Fade (_fade) - Multiplier for the overall strength of the light without affecting distance (which is controlled by Brightness (_light)
ZHLT Falloff (_falloff) - Light calculation falloff. Values:
- 0 = Default, Linear (Good for small lights)
- 1 = Inverse Linear
- 2 = Inverse Square (More akin to real-world light calculation)

Initially dark (1) - If this is enabled, the entity will need to be triggered to work.

Naming the light will make it ignore its Appearance (style). To get around this, use Custom Appearance (pattern) instead.
The Custom Appearance (pattern) property allows you to enter a string of up to 63 letters from a to z, representing brightness. If you entered 'abcdefghihgfedcba' then the light would go from bright to dim and back again and then repeat. To use this feature, you must name the light.
You can't have more than 4 named lights in the same visual area - because the compiler will have a difficult time allocating separate lightmap data for each light that can be turned on and off.
Glitch: Somehow, the engine (or rad compiler?) opts not to draw the light reflections/bright on the surface of nearby entities (anything 3D other than a brush) when there are SKY textured walls around the light entity. See an example here.
- Solution: Create a relatively large block anywhere between the light entity and the sky (usually, er, above the light entity); the "shadow" of this block will delimite where the glitch should be fixed. Apply SKIP texture on all of its faces and a black_HIDDEN on the face parallel to the light entity (usually bottom/top).