Speed Traps and Cameras

Reference for gameplay_speedTraps, which handles speed trap and red light camera trigger events. Fires visual flash effects and dispatches hooks when vehicles exceed speed limits.

Module Exports (M)

Hooks (Event Handlers)

Internals

• Camera distance limit: 100m - events are ignored if the vehicle is too far from camera
• Default red light trigger speed: 5 m/s
• Direction check: Uses dot product of trigger rotation vs vehicle velocity to ensure the vehicle is driving through the trap (not past it from the side)

Speed Trap Types

Light Flash Effects

When a trap triggers, the associated light object (named in speedTrapLightName) is briefly enabled:

• Speed camera: Single flash (0.1s on, then off)
• Red light camera: Double flash with delay based on vehicle speed (10 / speed seconds between flashes)

How It Works

1. onBeamNGTrigger receives data when a vehicle enters a BeamNGTrigger with speedTrapType set
2. Checks distance to camera, vehicle speed vs configured limit, and driving direction
3. For speed traps: fires onSpeedTrapTriggered hook with speed data
4. For red light cameras: checks core_trafficSignals state, fires onRedLightCamTriggered if red
5. Activates the flash light object via a coroutine job

Trigger Data Format

-- Example BeamNGTrigger dynamic fields:
{
  speedTrapType = "speed",       -- or "redLight"
  speedLimit = 11.176,           -- m/s
  speedLimitTolerance = 1.1,     -- m/s (optional, defaults to 10% of limit)
  speedTrapLightName = "speedTrapLight1",
  trafficSignalId = "signal1",   -- red light cameras only
  triggerSpeed = 5,              -- red light cameras only (optional)
}

Usage Example

-- Query all speed camera triggers on the current level
local traps = gameplay_speedTraps.getSpeedTrapsInCurrentLevel("speed")
for _, obj in pairs(traps) do
  log("I", "", "Speed trap: " .. obj:getName())
end

-- Listen for speed trap events
local function onSpeedTrapTriggered(data, speed, overSpeed)
  log("I", "", string.format("Caught at %0.1f m/s, over by %0.1f", speed, overSpeed))
end

See Also

• Gameplay Achievement - Related reference
• Gameplay City - Related reference
• discover - Discover / Experience System - Related reference
• Gameplay Systems Guide - Guide