WheelCollider
A special collider for vehicle wheels.
Read time 8 minutesLast updated 2 days ago
Definition
- Type: Class
- Namespace: UnityEngine
- Assembly: UnityEngine.VehiclesModule
- Inherits from: Collider
public class WheelCollider : Collider
Remarks
Wheel collider is used to model vehicle wheels. It simulates a spring and damper suspension setup, and uses a slip based tire friction model to calculate wheel contact forces.
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.
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 PhysicsMaterial settings. Simulation of different road materials is done by changing the _forwardFriction and _sidewaysFriction based on what material the wheel is hitting. and WheelFrictionCurve.
Additional Resources: WheelCollider.GetGroundHit
Properties
Property | Description |
|---|---|
| brakeTorque | Brake torque expressed in Newton metres. |
| center | The center of the wheel, measured in the object's local space. |
| forceAppPointDistance | Application point of the suspension and tire forces measured from the base of the resting wheel. |
| forwardFriction | Properties of tire friction in the direction the wheel is pointing in. |
| isGrounded | Indicates whether the wheel currently collides with something (Read Only). |
| mass | The mass of the wheel, expressed in kilograms. Must be larger than zero. Typical values would be in range (20,80). |
| motorTorque | Motor torque on the wheel axle expressed in Newton metres. Positive or negative depending on direction. |
| radius | The radius of the wheel, measured in local space. |
| rotationSpeed | Rotation speed of the wheel, measured in degrees per second. |
| rpm | Current wheel axle rotation speed, in rotations per minute (Read Only). |
| sidewaysFriction | Properties of tire friction in the sideways direction. |
| sprungMass | The mass supported by this WheelCollider. |
| steerAngle | Steering angle in degrees, always around the local y-axis. |
| suspensionDistance | Maximum extension distance of wheel suspension, measured in local space. |
| suspensionExpansionLimited | Limits the expansion velocity of the Wheel Collider's suspension. If you set this property on a Rigidbody that has several Wheel Colliders, such as a vehicle, then it affects all other Wheel Colliders on the Rigidbody. |
| suspensionSpring | The parameters of wheel's suspension. The suspension attempts to reach a target position by applying a linear force and a damping force. |
| wheelDampingRate | The damping rate of the wheel. Must be larger than zero. |
Methods
Method | Description |
|---|---|
| ConfigureVehicleSubsteps | Configure vehicle sub-stepping parameters. |
| GetGroundHit | Gets ground collision data for the wheel. |
| GetWorldPose | Gets the world space pose of the wheel accounting for ground contact, suspension limits, steer angle, and rotation angle (angles in degrees). |
| ResetSprungMasses | Reset the sprung masses of the vehicle. |
Inheritance
Operators
Operator | Description |
|---|---|
| operator == | Compares two object references to see if they refer to the same object. |
| bool | Determines whether the object exists. |
| operator != | Compares if two objects refer to a different object. |