Weather

Weather

Q3Rally can render rain and snow inside weather volumes: brush entities that mark where the weather happens.

Entities

Entity	Description
rally_weather_rain	Rain volume
rally_weather_snow	Snow volume

Key	Description
number	Base number of particles (density) for this volume

Spawnflag	Effect
1	Rain only: disables the visual impact splashes on water and ground. Wet-road physics and tyre spray stay active.

Snow volumes have no splashes. Other spawnflags are ignored.

How it behaves

• Volume matters. Particles only appear inside the brush. The client checks each particle position against the volume.
• Adaptive quality. Density is scaled per player by cg_atmosphericLevel (0 none, 1 low, 2 high, 3 ultra), frame rate and field of view. It's smoothed to avoid flicker, so weather can look slightly different on different machines.
• Culling. Particles outside the view cone or too far away are switched off or redistributed. A single huge volume over the whole map can look thinner than expected.
• Deterministic. Particle positions, colours and flake types depend on the zone and particle index, not on random numbers per frame. Every player sees the same picture.

🧪 Development build:

• Road physics: roads inside a rain volume become wet (less grip, tyre spray). Roads inside a snow volume get packed-snow grip and snow spray.
• Ambience: players inside a volume hear rain or snow ambience (players can turn it off with cg_weatherAudio 0).
• Dynamic weather: the server can switch each volume on and off during the match. See Server Configuration → Weather.

Mapper checklist

1. Place volumes along the driving line and the main sightlines instead of one giant box around the map.
2. Make the volumes tall enough that particles have room to fall into view.
3. Use number to balance density against performance.
4. Test with cg_atmosphericLevel set to 0, 1, 2 and 3 before release.
5. Check transitions in and out of the volumes, and (in the development build) grip and spray on the affected roads.

Related worldspawn keys

enableSnow, enableDust and enableBreath on the worldspawn turn on extra environmental effects for the whole map. See Race Track Entities → Worldspawn keys.

Example maps

• q3r_sk1 (Canyon Cruise): rain
• q3r_ridgeracer (Ridge Racer): snow