Table of Contents

Modules

NWH Vehicle Physics 2 is a collection of VehicleComponents. All aspects of it are a component - sound components, effect components, etc. - they all inherit from VehicleComponent. The only way that a module is different from an inbuilt component is that it can be added or removed as needed.
Modules carry over state system from the VehicleComponent which means that each module can be turned on or off, enabled or disabled or have LOD set.

Usage

Adding a new module.
ModuleManager inspector.

ModuleManager is a VehicleComponent that manages VehicleModules.
For more info on Modules check Modules page.

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Module Wrapper

Each module is wrapped in a MonoBehaviour wrapper called ModuleWrapper. This is a way to get around lack of multiple inhertance in C#.
VehicleModule inherits from VehicleComponent, but it also needs to be serialized and for that it needs to be a MonoBehaviour. The new attribute [SerializeReference] has been present in Unity since 2019.3 and original implementation used that but the amount of bugs and lack of backwards-compatibility with older versions of Unity resulted in the wrappers being used instead.

Scripting

Adding a Module

Adding modules after vehicle initialization is not supported! Consider adding the module before entering play mode or immediately after adding the VehicleController (from scripting), and keeping them Disabled until needed.

To add a module use:

 myVehicleController.gameObject.AddComponent<MyModuleWrapper>(); 

Example (adding an ABSModule):

 myVehicleController.gameObject.AddComponent<ABSModuleWrapper>(); 

Getting a Module

Modules are VehicleComponents wrapped in MonoBehaviour containers (wrappers).

 MyModule module = myVehicleController.GetComponent<MyModuleWrapper>().module as MyModule; 

Removing a Module

To remove a module use:

 Destroy(myVehicleController.GetComponent<MyModuleWrapper>()); 

If doing this during the runtime the module should simply be disabled instead. ModuleManager does not update the modules list during the runtime so removing the module will result in an error.

Enabling/Disabling a Module

Since modules inherits from VehicleComponent they also work on the same principle:

 myModule.VC_Enable(); 
 myModule.VC_Disable(); 

Note that disabling or enabling a module will have no effect while LODs are active for that module as the LOD system will override the manual settings while active.
To disable LODs for a module use:

 myModule.LodIndex = -1; 

Creating a New Module

Example module directory structure.

ABS Module

ABSModule inspector.

Anti-lock Braking System module.
Prevents wheels from locking up by reducing brake torque when slip reaches too high value.
Slip value above which ABS is activated can be adjusted through Slip Threshold field.

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Aerodynamics Module

AerodynamicsModule inspector.

Calculates and applies aerodynamic drag and downforce.

Drag
  • Drag depends on vehicle dimensions. Those can be adjusted under vehicle's Settings tab.
  • Drag is calculated bot in longitudinal and lateral directions. Intensity of drag can be adjusted through Frontal Cd and Side Cd (Cd = coefficient of drag) fields. Data for different vehicles is available here.
Downforce

Downforce is calculated in a simplified fashion by applying downforce to a number of points over the vehicle. In the simplest form a single downforce point at the center of the vehicle can be used, or one point at the front and one point at the end of the vehicle.

  • Vertical position of Downforce Points should be below the WheelController position, or even as low as the floor of the vehicle. This is because all the force is applied in a single point which, if applied too high, can cause the vehicle to snap oversteer when changing direction.
  • Downforce is not dependent on vehicle shape or dimensions. It is calculated through Downforce Points and Max Downforce Speed.
  • Downforce increases exponentially from 0 to Max Downforce Speed at which it reaches Max Force value.
  • Enable Gizmos to be able to see downforce points (red sphere).
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Cruise Control Module

CruiseControl module.
  • Cruise Control implemented through a PID controller.
  • Target Speed value sets the speed that cruise control will try to achieve. Ignored in reverse.
  • Can apply throttle and braking.
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ESC Module

ESC module inspector.

Electronic Stability Control (ESC) module.
Applies braking on individual wheels to try and stabilize the vehicle when the vehicle velocity and vehicle direction do not match.

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Motorcycle Module

MotorcycleModule inspector.

Adds additional motorcycle balancing, steering and lean functionality to the NWH Vehicle Physics. The rest of the setup is similar to the conventional vehicle, just with two wheels and transmission outputting directly to the rear wheel, without the use of differentials.

Trikes can be implemented without this module as they do not require the additional functionality.

Field explanations can be seen by hovering over fields in the Unity inspector.

Lean Controller

Lean is implemented through a PID controller and is one of the more important settings of the module. It determines in which manner the vehicle will lean and balance. PID controller is required because the balancing is done through physics (AddTorque). The tuning of the said controller requires a bit of tweaking (adjustable at runtime) but the default settings should be adequate for a vast majority of motorcycles.

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Arcade Module

ArcadeModule inspector.

Module containing a collection of assists aimed at achieving arcade-like behavior from the vehicles. Current functionality:

Steer Assist

Adds artificial steer torque to the vehicle, independent of the tire grip. This helps rotate the vehicle.

Drift Assist

Prevents the vehicle from drifting over the set angle, effectively preventing spin-outs.

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Flip Over Module

FlipOver module inspector.

If the vehicle gets flipped over FlipOverModule will flip it to be right side up again.

  • Flip Over Activation determines if the flip over will happen automatically, or if it will wait for user FlipOver input once it detects that the vehicle is flipped over.
  • Flip Over Type determines if the vehicle will get slowly rolled over or instantly flipped over in place.
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Fuel Module

FuelModule inspector.

Module for simulating the fuel system in a vehicle. Fuel consumption gets automatically generated from engine efficiency (average ICE efficiency is used) and fuel energy content. Consumption can be adjusted through Consumption Multiplier.

  • Prevents engine from running when out of fuel.
  • Amount indicates the amount of fuel currently in the tank while Capacity indicates maximum tank capacity.
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MetricsModule inspector.

MetricsModule is used to record data about vehicle behavior. That data can then be used for display purposes, achievements or e.g. a boost system using NOS.

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NOSModule inspector.

NOS (Nitrous Oxide System) module.

  • Adds power to the engine.
  • Affects engine sound by increasing volume.
  • Has it's own SoundComponent which imitates hiss caused by releasing highly pressurised NOS from the bottle.
  • If ExhaustFlash effect is enabled it will be active while NOS is active.
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Rigging Module

RiggingModule inspector.

Module used to animate rigged models by moving the axle/wheel bones.

  • Axle Bones - list of handles controlling the axle bones. Each item is a single axle handle.
  • Wheel Bones - list of handles controlling the wheel bones. Each item is a single wheel bone handle.
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Speed Limiter Module

SpeedLimiter module inspector.

Module that limits vehicle speed to the set speed limit.
Only limits throttle application, does not apply brakes. For that use CruiseControlModule.

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TCS Module

TCSModule inspector.

Traction Control System (TCS) module. Reduces engine throttle when excessive slip is present.

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Trailer Module

TrailerModule inspector.

TrailerModule works in tandem with TrailerHitchModule. VehicleController that has TrailerModule is able attach to a VehicleController that has TrailerHitchModule.

  • One vehicle can have both TrailerHitchModule and TrailerModule.
  • Attachment Point is the point at which the trailer will be attached to the towing vehicle. The script creates a SphereCollider trigger at this point which detects if the TrailerHitchModule Attachment Point is nearby. Attachment Point needs to be a child of the GameObject containing the TrailerModule.
  • Trailer Stand is the object which will be enabled if the trailer is detached and vice versa. It prevents the trailer from tipping forward on trailers with only the back axle.
  • If Synchronize Gear Shifts is enabled the trailer object will be kept in the same gear. This allows for powered trailer or vehicles that are constructed out of two Rigidbodies.

Also check Trailer Hitch module.

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Trailer Hitch Module

TrailerHitch module.

VehicleController with TrailerHitchModule can attach a VehicleController with TrailerModule as a trailer.

  • Both TrailerHitchModule and TrailerModule can be present on one vehicle at the same time.
  • AttachmentPoint is the point at which the trailer will be attached. The trailer will be moved so that both trailer and hitch AttachmentPoints are at the same position. This is where the physics joint gets created. Attachment Point needs to be a child of the GameObject containing the TrailerHitchModule.
  • On initialization a SphereCollider trigger is created at the attachment point. This is used to detect if a TrailerModule is nearby. When there is overlap between the TrailerModule and TrailerHitchModule triggers, pressing 'T' (default key mapping) will connect the trailer.

Also check Trailer module.

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