J-Turn Detection

Reference for gameplay_statisticModules_watchJturn, a statistic submodule that detects J-turn maneuvers (reversing at speed, then spinning 180° to drive forward).

Module Exports (M)

Hooks (Event Handlers)

Internals

Detection Algorithm

The module tracks the player vehicle through a state machine:

1. Idle - Waiting for reverse driving at speed (≥ 8 m/s)
2. Triggered - Vehicle is driving backward (direction vector · velocity < -0.96). Records the backing direction
3. Completion check - While triggered, checks if the vehicle now drives forward (dot > 0.96) AND the forward direction is nearly opposite to the original backing direction (dot < -0.90)
4. Timeout - If more than 4 seconds pass since the last backward detection, the attempt is cancelled

Constants

Metric Recorded

On successful J-turn detection:

gameplay_statistic.metricAdd("vehicle/jturn", 1)

How It Works

1. The workload function is registered with gameplay_statistic.addSchedule() during module load
2. Each frame (round-robin), checks the player vehicle's velocity vs direction vectors
3. When the vehicle drives backward fast enough, records the backing direction and enters triggered state
4. If the vehicle subsequently drives forward in the opposite direction (within timeout), records a J-turn
5. Vehicle resets and switches cancel any in-progress detection

Usage Example

-- This module is auto-loaded by gameplay_statistic
-- To check J-turn count:
local jturnData = gameplay_statistic.metricGet("vehicle/jturn", true)
if jturnData then
  log("I", "", "J-turns: " .. jturnData.value)
end

See Also

• gameplay/statisticModules/watchRollover - Rollover Detection - Related reference
• Gameplay Systems Guide - Guide