env_fog #

Use env_fog to put a global fog on the map. Set the entity name to make it toggleable by triggers.

Fog covers the whole map (including the indoor areas). There’s currently no alternative to it.

You can use several env_fog entities on one map, but it’s better to make sure that only one is active at a time.

Beams may look weird in the fog (the transparent part won’t render correctly). There’s no fix for this. Avoid using beams in the foggy areas.

The GL Fog type option used to allow selecting between Linear and Exponential fog (OpenGL terms), but after the Half-Life anniversary update it doesn’t work as expected anymore. Linear fog uses Start distance and End distance values and it will look for a player like a wall of color starting with a certain distance. Exponential fog relies only on density, which should be a number smaller than 0.01, and it’s considered to be more realistic.

• By default in GoldSource the fog is exponential (exponential-squared to be precise).
• On steam_legacy branch the custom fog type will be applied as expected.
• On the current (anniversary) version the fog will always be exponential if the shaders are on. Otherwise the behavior is the same as on steam_legacy.
• To get the linear fog on the current version of GoldSource with shaders on you must copy platform/gl_shaders subdirectory to your mod and edit the fs_world.frag to always use the linear fog. Note that it will force the fog to the certain type disregarding the configured type in the env_fog.

Spawnflags #

• Start active - whether the fog is active at the start of the map. Unnamed fogs are always active.
• Affect skybox - whether the skybox is covered by fog as well.

Reaction to use-type #

Toggles the fog depending on the input use-type.