VehicleWheel

Inherits: Spatial < Node < Object

Physics object that simulates the behavior of a wheel.

Description

This node needs to be used as a child node of VehicleBody and simulates the behavior of one of its wheels. This node also acts as a collider to detect if the wheel is touching a surface.

Note: This class has known issues and isn't designed to provide realistic 3D vehicle physics. If you want advanced vehicle physics, you will probably have to write your own physics integration using another PhysicsBody class.

Properties

float	brake	0.0
float	damping_compression	0.83
float	damping_relaxation	0.88
float	engine_force	0.0
float	steering	0.0
float	suspension_max_force	6000.0
float	suspension_stiffness	5.88
float	suspension_travel	5.0
bool	use_as_steering	false
bool	use_as_traction	false
float	wheel_friction_slip	10.5
float	wheel_radius	0.5
float	wheel_rest_length	0.15
float	wheel_roll_influence	0.1

Methods

float	get_rpm ( ) const
float	get_skidinfo ( ) const
bool	is_in_contact ( ) const

Property Descriptions

float brake

Default	0.0
Setter	set_brake(value)
Getter	get_brake()

Slows down the wheel by applying a braking force. The wheel is only slowed down if it is in contact with a surface. The force you need to apply to adequately slow down your vehicle depends on the RigidBody.mass of the vehicle. For a vehicle with a mass set to 1000, try a value in the 25 - 30 range for hard braking.

float damping_compression

Default	0.83
Setter	set_damping_compression(value)
Getter	get_damping_compression()

The damping applied to the spring when the spring is being compressed. This value should be between 0.0 (no damping) and 1.0. A value of 0.0 means the car will keep bouncing as the spring keeps its energy. A good value for this is around 0.3 for a normal car, 0.5 for a race car.

float damping_relaxation

Default	0.88
Setter	set_damping_relaxation(value)
Getter	get_damping_relaxation()

The damping applied to the spring when relaxing. This value should be between 0.0 (no damping) and 1.0. This value should always be slightly higher than the damping_compression property. For a damping_compression value of 0.3, try a relaxation value of 0.5.

float engine_force

Default	0.0
Setter	set_engine_force(value)
Getter	get_engine_force()

Accelerates the wheel by applying an engine force. The wheel is only speed up if it is in contact with a surface. The RigidBody.mass of the vehicle has an effect on the acceleration of the vehicle. For a vehicle with a mass set to 1000, try a value in the 25 - 50 range for acceleration.

Note: The simulation does not take the effect of gears into account, you will need to add logic for this if you wish to simulate gears.

A negative value will result in the wheel reversing.

float steering

Default	0.0
Setter	set_steering(value)
Getter	get_steering()

The steering angle for the wheel. Setting this to a non-zero value will result in the vehicle turning when it's moving.

float suspension_max_force

Default	6000.0
Setter	set_suspension_max_force(value)
Getter	get_suspension_max_force()

The maximum force the spring can resist. This value should be higher than a quarter of the RigidBody.mass of the VehicleBody or the spring will not carry the weight of the vehicle. Good results are often obtained by a value that is about 3× to 4× this number.

float suspension_stiffness

Default	5.88
Setter	set_suspension_stiffness(value)
Getter	get_suspension_stiffness()

This value defines the stiffness of the suspension. Use a value lower than 50 for an off-road car, a value between 50 and 100 for a race car and try something around 200 for something like a Formula 1 car.

float suspension_travel

Default	5.0
Setter	set_suspension_travel(value)
Getter	get_suspension_travel()

This is the distance the suspension can travel. As Godot units are equivalent to meters, keep this setting relatively low. Try a value between 0.1 and 0.3 depending on the type of car.

bool use_as_steering

Default	false
Setter	set_use_as_steering(value)
Getter	is_used_as_steering()

If true, this wheel will be turned when the car steers. This value is used in conjunction with VehicleBody.steering and ignored if you are using the per-wheel steering value instead.

bool use_as_traction

Default	false
Setter	set_use_as_traction(value)
Getter	is_used_as_traction()

If true, this wheel transfers engine force to the ground to propel the vehicle forward. This value is used in conjunction with VehicleBody.engine_force and ignored if you are using the per-wheel engine_force value instead.

float wheel_friction_slip

Default	10.5
Setter	set_friction_slip(value)
Getter	get_friction_slip()

This determines how much grip this wheel has. It is combined with the friction setting of the surface the wheel is in contact with. 0.0 means no grip, 1.0 is normal grip. For a drift car setup, try setting the grip of the rear wheels slightly lower than the front wheels, or use a lower value to simulate tire wear.

It's best to set this to 1.0 when starting out.

float wheel_radius

Default	0.5
Setter	set_radius(value)
Getter	get_radius()

The radius of the wheel in meters.

float wheel_rest_length

Default	0.15
Setter	set_suspension_rest_length(value)
Getter	get_suspension_rest_length()

This is the distance in meters the wheel is lowered from its origin point. Don't set this to 0.0 and move the wheel into position, instead move the origin point of your wheel (the gizmo in Godot) to the position the wheel will take when bottoming out, then use the rest length to move the wheel down to the position it should be in when the car is in rest.

float wheel_roll_influence

Default	0.1
Setter	set_roll_influence(value)
Getter	get_roll_influence()

This value affects the roll of your vehicle. If set to 1.0 for all wheels, your vehicle will be prone to rolling over, while a value of 0.0 will resist body roll.

Method Descriptions

float get_rpm ( ) const

Returns the rotational speed of the wheel in revolutions per minute.

float get_skidinfo ( ) const

Returns a value between 0.0 and 1.0 that indicates whether this wheel is skidding. 0.0 is skidding (the wheel has lost grip, e.g. icy terrain), 1.0 means not skidding (the wheel has full grip, e.g. dry asphalt road).

bool is_in_contact ( ) const

Returns true if this wheel is in contact with a surface.