The tyVehicle helper is the root object of a PhysX vehicle rig. It holds the list of every vehicle chassis, joint, hitch and strut, and is the object added to a PhysX Vehicle operator’s vehicle list for simulation. Vehicles in a simulation will be instantiated such that their rig particles will be positioned/oriented relative to their root particle the same way the vehicle part helpers are positioned/oriented relative to the tyVehicle helper. In that sense, the tyVehicle helper acts like the base pivot of the vehicle rig.
The tyVehicle helper is the only vehicle helper that can be created directly from the Create panel. All other vehicle helpers (chassis, turrets, treads, wheels, etc) must be created either from the “Create vehicle part…” menu of either the tyVehicle helper, or from similar menus available in other vehicle helpers (ex: a tyVehicleTurretBarrel helper can only be created from the “Create barrel” option of the tyVehicleTurret helper, which itself can only be created from the “Create chassis part…” menu of a tyVehicleChassis helper, which itself can only be created from the “Create vehicle part” menu of a tyVehicle helper. This system ensures that child helpers are only creatable by the parent helpers that they can be added to (ex: a wheel helper cannot be used to create a turret helper - only a chassis can create a turret helper, because turrets are always attached to a chassis).
Base parts are those that are not dependent on a single type of other vehicle part. For example, a chassis is not dependent on another vehicle part, so it must be added to a tyVehicle helper in order to be part of the rig. Hitches, joints, struts and widgets are also not dependent on a single vehicle part (or single type of vehicle part, in the case of widgets), and so they must be added to a tyVehicle helper in order to be considered part of the vehicle rig. All other vehicle parts must be added to the part that they’re dependent on, in order to be included in the rig (ex: a turret must be added to the parts list of its chassis, because turrets are always dependent on a chassis in order to be part of a vehicle rig). In this way, the rig is not made up of a single list of parts stored in a tyVehicle helper, but instead a hierarchy of parts, starting with the base parts of a tyVehicle helper. For example, a turret that is added to the parts list of a chassis, which is added to the parts list of a tyVehicle helper will be included in the rig, even though the turret itself is not found in the parts list of the tyVehicle helper. When vehicles are instantiated, the PhysX Vehicle operator starts by instantiating all base parts of the corresponding tyVehicle helper, and then walks through the parts list of each base part, and instantiates those parts, and so on.
Show icon: controls whether the tyVehicle icon is displayed in the viewport.
Icon size: controls the size of the tyVehicle icon.
If a PhysX Vehicle operator fails to instantiate a vehicle, always check the status text of the corresponding tyVehicle helper - it will explain how to fix whatever issue is preventing the simulation from creating the vehicle rig. For example, if you’ve added a joint helper to the tyVehicle parts list but forgot to assign the front/rear helpers to the joint, instantiation of the vehicle in a simulation will fail and the status text will be colored red, explaining the error. The status text may also display warnings (ex: if vehicle parts have no meshes assigned), but warnings will not prevent vehicle instantiation in a simulation.
The settings on this rollout are the vehicle’s base engine/handling values. A PhysX Vehicle operator’s own Engine Settings rollout can override these values for every vehicle it simulates, but when an override is left disabled, these per-vehicle values are used instead - allowing different vehicles in the same flow to have their own distinct handling.
Drive torque: the torque applied to driven wheels under full throttle.
Brake torque: the torque applied to wheels under full braking.
Boost multiplier: the multiplier applied to drive torque while boost input is active.
Forward velocity: the maximum forward speed of the vehicle.
Reverse velocity: the maximum reverse speed of the vehicle.
Boost multiplier: the multiplier applied to the maximum forward velocity while boost input is active.
Response: controls how quickly throttle input ramps up to its commanded value, rather than being applied instantly. Smaller values produce a snappier response.
Boost multiplier: the multiplier applied to throttle response while boost input is active.
Steering response: controls how quickly steering input ramps toward its commanded angle.
Steering return: controls how quickly the steering angle returns toward center once steering input is released.