Physics: VehicleSpec
In a pack: the physics section of vehicles/<name>.json, the field names the table's first column, any left out keeping the T15's; angles in degrees, speeds in km/h, steerGrip in g, the rest model frame and SI (kg, N, m, s, rpm). In Java: start from VehicleSpec.fromT15(), change it, build(), all SI and radians.
| Field | Meaning | White-box coupe |
|---|---|---|
mass | kerb mass, kg | 1500 |
ix iy iz | moments of inertia about the three axes, kg·m² | 2000 / 2300 / 520 |
comY comZ | centre of mass height and fore-aft position | 0.48 / 0.05 |
frontZ rearZ | the axles' Z (front negative; their difference is the wheelbase) | −1.30 / 1.30 |
halfTrack | half the track | 0.74 |
radius | tyre radius (245/45 R17 ≈ 0.33) | 0.33 |
bump droop | suspension travel up and down | 0.08 / 0.10 |
springFront/Rear dampFront/Rear | per wheel: spring rate N/m, damping N·s/m | 36000 / 38000, 2700 / 2900 |
antiRollFront/Rear | anti-roll bars | 22000 / 12000 |
maxSteer | front wheel lock | 34° |
steerGrip | tyre side grip (an acceleration) | 0.95 g |
topSpeed | top speed, m/s | 230 km/h |
torqueRpm torqueNm | the torque curve (pairs) | V8 |
idleRpm cutRpm stallRpm | idle, cut-off, stall | 750 / 6300 / 400 |
starterTorque starterRpm | the starter | 90 / 250 |
startFlare | the flare as it fires (rpm above idle): held 0.3 s, then falling back to idle over about a second, a sports car's bark at start-up, heard from the engine's own loops; 0 for none | 0 |
preheat | a diesel's glow time (s); 0 for petrol | 0 |
gears reverseGear finalDrive | gear ratios, reverse, final drive | 5-speed manual |
clutchTorque | the torque the clutch carries | 600 |
automatic | an automatic: it picks its forward gears; the shift keys become paddles that hold a gear for 6 s | false |
allWheel | all-wheel drive all the time (no transfer case; the drive split by the wheels' loads) | false |
tractionControl | traction control: the throttle eased while a driven wheel spins | false |
stabilityControl | stability control: the tail sliding out takes the throttle off and brakes the outer front wheel | false |
electricParkingBrake | an electric parking brake: pulled while moving it brakes all four wheels with ABS, no rear wheels locked; standing it holds as usual. The speedometer reads all four wheels | false |
fourWheelSpeed | the top speed for engaging 4WD; 0: rear drive only, no transfer case | 0 |
lowRange lowRangeSpeed | low-range ratio and its speed limit (1 and 0 for rear drive) | 1 / 0 |
brakeForce brakeFront | total brake force, front share | 16000 / 0.62 |
rolling drag | rolling resistance, air drag | 0.013 / 0.45 |
fuelPerKwh fuelIdle | fuel use | 0.30 / 0.8 |
hull | the body's contact points (rolling over, walls, other vehicles); see below | boxHull(...) |
In a pack "hull": {"box": [halfWidth, frontZ, rearZ, bottom, belt, cabinHalfWidth, cabinFrontZ, cabinRearZ, roof]} (Java: VehicleSpec.boxHull(...), the same nine) makes one: the lower body a box, the cabin a smaller box on it.