WheelCollider Manual     Reference     Scripting  
Scripting > Runtime Classes > WheelCollider
WheelCollider Class, inherits from Collider

A special collider for vehicle wheels.

Wheel collider is used to model vehicle wheels. It functions similar to the RaycastCollider, but also has wheel physics and slip based tire friction model built in. In most cases WheelCollider is more accurate and easier to use as well.

Wheel's collision detection is performed by casting a ray from center downwards the local y-axis. The wheel has a radius and can extend downwards by suspensionDistance amount.

The wheel is controlled with motorTorque, brakeTorque and steerAngle properties.

Wheel collider computes friction separately from the rest of physics engine, using a slip based friction model. This allows for more realistic behaviour, but makes wheel colliders ignore standard PhysicMaterial settings. Simulation of different road materials is done by changing the forwardFriction and sidewaysFriction based on what material the wheel is hitting. See Also: GetGroundHit and WheelFrictionCurve.

Variables
center

The center of the wheel, measured in the object's local space.

radius

The radius of the wheel, measured in local space.

suspensionDistance

Maximum extension distance of wheel suspension, measured in local space.

suspensionSpring

The parameters of wheel's suspension. The suspension attempts to reach a target position

mass

The mass of the wheel. Must be larger than zero.

forwardFriction

Properties of tire friction in the direction the wheel is pointing in.

sidewaysFriction

Properties of tire friction in the sideways direction.

motorTorque

Motor torque on the wheel axle. Positive or negative depending on direction.

brakeTorque

Brake torque. Must be positive.

steerAngle

Steering angle in degrees, always around the local y-axis.

isGrounded

Indicates whether the wheel currently collides with something (Read Only).

rpm

Current wheel axle rotation speed, in rotations per minute (Read Only).

Functions
GetGroundHit

Gets ground collision data for the wheel.

Inherited members
Inherited Variables
attachedRigidbody

The rigidbody the collider is attached to.

isTrigger

Is the collider a trigger?

material

The material used by the collider.

sharedMaterial

The shared physic material of this collider.

bounds

The world space bounding volume of the collider.

transform

The Transform attached to this GameObject (null if there is none attached).

rigidbody

The Rigidbody attached to this GameObject (null if there is none attached).

camera

The Camera attached to this GameObject (null if there is none attached).

light

The Light attached to this GameObject (null if there is none attached).

animation

The Animation attached to this GameObject (null if there is none attached).

constantForce

The ConstantForce attached to this GameObject (null if there is none attached).

renderer

The Renderer attached to this GameObject (null if there is none attached).

audio

The AudioSource attached to this GameObject (null if there is none attached).

guiText

The GUIText attached to this GameObject (null if there is none attached).

networkView

The NetworkView attached to this GameObject (Read Only). (null if there is none attached)

guiTexture

The GUITexture attached to this GameObject (Read Only). (null if there is none attached)

collider

The Collider attached to this GameObject (null if there is none attached).

hingeJoint

The HingeJoint attached to this GameObject (null if there is none attached).

particleEmitter

The ParticleEmitter attached to this GameObject (null if there is none attached).

gameObject

The game object this component is attached to. A component is always attached to a game object.

tag

The tag of this game object.

name

The name of the object.

hideFlags

Should the object be hidden, saved with the scene or modifyable by the user?

Inherited Functions
ClosestPointOnBounds

The closest point to the bounding box of the attached collider.

Raycast

Casts a Ray that ignores all Colliders except this one.

GetComponent

Returns the component of Type type if the game object has one attached, null if it doesn't.

GetComponentInChildren

Returns the component of Type type in the GameObject or any of its children using depth first search.

GetComponentsInChildren

Returns all components of Type type in the GameObject or any of its children.

GetComponents

Returns all components of Type type in the GameObject.

CompareTag

Is this game object tagged tag?

SendMessageUpwards

Calls the method named methodName on every MonoBehaviour in this game object and on every ancestor of the behaviour

SendMessage

Calls the method named methodName on every MonoBehaviour in this game object.

BroadcastMessage

Calls the method named methodName on every MonoBehaviour in this game object or any of its children.

GetInstanceID

Returns the instance id of the object.

Inherited Messages Sent
OnTriggerEnter

OnTriggerEnter is called when the Collider other enters the trigger.

OnTriggerExit

OnTriggerExit is called when the Collider other has stopped touching the trigger.

OnTriggerStay

OnTriggerStay is called almost all the frames for every Collider other that is touching the trigger.

OnCollisionEnter

OnCollisionEnter is called when this collider/rigidbody has begun touching another rigidbody/collider.

OnCollisionExit

OnCollisionExit is called when this collider/rigidbody has stopped touching another rigidbody/collider.

OnCollisionStay

OnCollisionStay is called once per frame for every collider/rigidbody that is touching rigidbody/collider.

Inherited Class Functions
operator bool

Does the object exist?

Instantiate

Clones the object original and returns the clone.

Destroy

Removes a gameobject, component or asset.

DestroyImmediate

Destroys the object obj immediately. It is strongly recommended to use Destroy instead.

FindObjectsOfType

Returns a list of all active loaded objects of Type type.

FindObjectOfType

Returns the first active loaded object of Type type.

operator ==

Compares if two objects refer to the same

operator !=

Compares if two objects refer to a different object

DontDestroyOnLoad

Makes the object target not be destroyed automatically when loading a new scene.