Vehicle Data Setup

In the Vehicle Data Setup module, you will configure essential vehicle data that plays a crucial role in defining your vehicle’s behavior. This includes the torque curve, max RPM, gearbox settings, steering, and more. Let’s delve into the essential components:

Torque Curve and Max RPM

One of the fundamental aspects of a vehicle’s performance is its torque curve and maximum RPM (Revolutions Per Minute). It’s essential for a realistic engine simulation that the torque curve reaches zero or approaches zero around or before the maximum RPM. This aligns with the limitations of real-world engines.

To create a torque curve for your vehicle, you can reference an existing curve from a similar vehicle or use a curve that matches the characteristics of your specific vehicle. Copy and paste this curve into the engine for accurate representation.

Gearbox Configuration

The gearbox configuration is another critical element of your vehicle setup. You can define an array of gears, where the gear with a ratio of 0 is considered idle. Gears before this point represent reverse, while gears after this point represent forward motion. Each gear has an RPM ratio for gear changes, ranging from 0 to 1.

It’s important to note that the gear ratio is influenced by the differential ratio and the final drive ratio, which, in turn, is affected by the wheel radius. Tuning the differential ratio allows you to fine-tune the vehicle’s power-to-maximum-speed ratio. If you notice that your RPM is changing at a rate different from your expectations, this parameter should be adjusted accordingly.

Steering Curve

To enhance your vehicle’s control and realism, it’s recommended to implement a steering curve. This curve reduces the sensitivity of steering input relative to the vehicle’s speed. You might have observed this phenomenon when driving your own vehicle, where minimal steering input is required at high speeds due to subconscious adjustments.

With these essential components and configurations, you can fine-tune your vehicle’s behavior and performance to match your project’s requirements. Each parameter plays a crucial role in creating an authentic and enjoyable vehicle simulation.

Params and their explnatation Explanation

Parameter	Type	Explanation
EngineTorqueCurve	FRuntimeFloatCurve	Torque curve in Newtons per Meter.
ZeroRpmWhenShifting	bool	Set RPM to zero when shifting.
IdleRpm	float	Idle RPM (can be zero).
MaxRpm	float	Maximum RPM, generally where torque curve reaches zero torque.
EngineInertia	float	How fast the engine RPM can change, used to stabilize RPM ranges from 0 to 1.
GearBoxData	UModularGearBox (Instanced)	Gearbox data for defining gears.
SuspensionTraceTypeQuery	TEnumAsByte<ETraceTypeQuery>	Suspension trace type.
ScaleTireFrictionWithSurfaceAngle	bool	Divide available tire grip between drive wheels based on surface angle (realistic value is true).
ScaleDriveTorqueToNumberOfWheels	bool	Divide drive torque among the number of wheels touching the ground to simulate a differential.
SteerCurve	FRuntimeFloatCurve	Steering curve for controlling steering input relative to vehicle speed.
SteerType	TEnumAsByte<EModularSteerType>	Steering method.
TrackWidth	float	Lateral distance between two wheels on the same axle.
WheelBase	float	Distance between two axles.
SteerInputRise	float	How fast the input should rise, multiplied by DeltaTime.
SteerInputFall	float	How fast the input should fall, multiplied by DeltaTime.
CounterSteerMultiplier	float	Multiplier for input when the vehicle is sliding and trying to reorient itself.
bReverseAsBrake	bool	Brake input will put the vehicle in reverse once it has stopped.
WrongDirectionThreshold	float	Auto-brake when the vehicle’s forward speed is opposite of player input by at least this much (cm/s).
StopThreshold	float	Auto-brake when the absolute vehicle forward speed is less than this (cm/s).
IdleBrakeInput	float	How much to press the brake when the player has released the throttle.
AIMaxSteerMultiplier	float	Multiplier for AI vehicles to make steering easier.
ReverseThreshold	float	Threshold for reversing based on dot product between forward vector and destination (-1 to 1).
TurnThreshold	float	Threshold for slow steering based on dot product between forward vector and destination (-1 to 1). Should be higher than ReverseThreshold.
DesireSpeedNormal	float	Desired speed when moving forward normally (km/h).
DesireSpeedTurning	float	Desired speed when turning towards a goal (should be small to steer fully).
DesireSpeedTurningAround	float	Desired speed when performing a U-turn (km/h).
DesireSpeedNearGoal	float	Desired speed when near a goal, calculated based on distance (cm) and desired speed.
NearGoalDistance	float	Distance (cm) considered “near goal” to apply near goal speed.
FullThrottleSpeed	float	Speed difference that triggers flooring the gas.
AITraceLength	float	Length of the avoidance trace (cm).
AITraceSpeedMultiplier	float	Multiplier for trace length based on vehicle speed.
VehicleFrontArea	float	Frontal area for calculating air resistance (Meters^2).
AirDensity	float	Air density (typically equal to Earth’s air density).
AirDragCoefficient	float	The drag coefficient for air resistance (dimensionless).
NetworkMode	TEnumAsByte<EVehicleNetworkMode>	Network mode for vehicle replication.

These parameters will help you fine-tune your vehicles and define their behavior within your game. Adjust them to achieve the desired performance and realism.