WheelHit Struct

Contact information for the wheel, reported by WheelCollider.

Friction for the WheelCollider is computed separately from the rest of the physics, using a slip based tire friction model. This allows for more realistic behaviour, but makes wheel colliders ignore standard PhysicMaterial settings.

The way to simulate different ground materials is to query WheelCollider for its collision information (see WheelCollider.GetGroundHit). Usually you get the other collider the wheel is hitting, and modify wheel's forwardFriction and sidewaysFriction based on ground's material.

The other members of WheelHit structure are usually queried for information purposes or special effects. E.g. a "slipping tire" sound can be played if forwardSlip or sidewaysSlip exceed some threshold.

See Also: WheelCollider.GetGroundHit.

collider	The other Collider the wheel is hitting.
point	The point of contact between the wheel and the ground.
normal	The normal at the point of contact.
forwardDir	The direction the wheel is pointing in.
sidewaysDir	The sideways direction of the wheel.
force	The magnitude of the force being applied for the contact.
forwardSlip	Tire slip in the rolling direction. Acceleration slip is negative, braking slip is positive.
sidewaysSlip	Tire slip in the sideways direction.