Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
class	SceneKit	MBS Mac64bit Plugin	20.2	✅ Yes	❌ No	❌ No	✅ Yes	Desktop & iOS

The appearance and physical characteristics of an individual wheel associated with an physics vehicle behavior.

To use wheels in a vehicle simulation, include them when creating an SCNPhysicsVehicle object with the vehicleWithChassisBody / Constructro initializer, then add the vehicle object to your scene’s physics world using the physics world’s addBehavior method.

Creating a Wheel
You create a wheel with an SCNNodeMBS object whose contents provide the wheel’s visual representation—a geometry that rotates when the simulated vehicle rolls along a surface. The node representing a wheel must be a child of the node containing the physics body that serves as the vehicle’s chassis, and each wheel in a vehicle must reference a unique node. Typically, you load a scene file that contains a node hierarchy representing the vehicle and all of its wheels. Next, you designate which nodes serve as the body and wheels.
Because the SCNPhysicsVehicleMBS behavior that a wheel is attached to manages its participation in the physics simulation, you don’t need to attach a physics body to the SCNNodeMBS object representing a wheel.

Changing a Wheel’s Physical Properties
The properties of a wheel define the geometry of its connection to the vehicle and simulate its size, traction, and suspension. You can change these properties after the wheel and the vehicle containing it have been added to the physics world. In this way, you can simulate effects such as variable suspension and flat tires.

Note
Vehicles and their wheels have several properties measured in real-world units (meters, centimeters, and newtons) with default values that produce realistic behavior for vehicles of size similar to an average automobile. If you design your scene on a different scale, proportionally change the values of these properties to fit the desired behavior of your app or game.