env_glow
env_glow is a point entity available in all 
GoldSrc games. The env_glow entity is much like the env_sprite in that it places a sprite within the map. The only differences seem to be that the env_glow does not animate its sprite, it cannot be triggered, and that it lacks some of the options that the env_sprite has.
Key Values
Targetname:
- Name
(targetname)<targetname> - The targetname that other entities refer to this entity by.
- Sprite Name
(model)<sprite> - This defines which sprite file will be displayed by the entity.
- Scale
(scale)<integer> - Sets the scale of the sprite, in the form of a size multiplier.
- Render FX
(renderfx)<choices> - Render FX mode to use, for special effects.
Value Description 0 Normal 1 Slow Pulse 2 Fast Pulse 3 Slow Wide Pulse 4 Fast Wide Pulse 5 Slow Fade Away 6 Fast Fade Away 7 Slow Become Solid 8 Fast Become Solid 9 Slow Strobe 10 Fast Strobe 11 Faster Strobe 12 Slow Flicker 13 Fast Flicker 14 Constant Glow 15 Distort 16 Hologram (Distort + fade)
- Render Mode
(rendermode)<choices> - Render Mode to use.
Value Description 0 Normal 1 Color 2 Texture 3 Glow 4 Solid 5 Additive
- FX Amount (1-255)
(renderamt)<integer> - Controls transparency when using another render mode then normal. 0 is completely invisible, and 255 is opaque.
- FX Color (R G B)
(rendercolor)<color255> - Color to use by the specified render mode.
Also used to control the speed of scrolling textures; seefunc_conveyorfor more information.
