Class Bone
Represents a single animated bone element in the vehicle rigging system.
Namespace: NWH.VehiclePhysics2.Modules.Rigging
Assembly: NWH.VehiclePhysics2.dll
Syntax
[Serializable]
public class BoneRemarks
A Bone is a fundamental unit of the rigging system that defines how a single transform (such as a suspension arm, axle, or linkage) should be animated based on the position of one or more target transforms. Each bone can be configured to look at its target, stretch to maintain connection, or position itself between two targets.
Animation Modes: - Look At: Rotates the bone to face the target transform - Stretch: Scales the bone along its Z-axis to maintain connection with the target - Double-Sided: Positions the bone midway between two targets (useful for axles)
Common Applications: - Suspension arms tracking wheel movement - Driveshafts connecting transmission to wheels - Steering linkages following wheel rotation - Shock absorbers compressing with suspension travel
Fields
doubleSided
Position the bone centered between two target points.
Declaration
[Tooltip("Should the object be positioned between two points. Also affects position besides rotation.")]
public bool doubleSidedField Value
| Type | Description |
|---|---|
| bool |
Remarks
When enabled, the bone is positioned at the midpoint between targetTransform and targetTransformB, and rotated to look at targetTransform. This is useful for axles or other components that span between two moving parts (like wheels).
This overrides normal position behavior and requires targetTransformB to be assigned. Typically used for components like drive axles connecting left and right wheels.
lookAtTarget
Rotate the bone to face the target transform.
Declaration
[Tooltip("Should the object be rotated to look at the target?")]
public bool lookAtTargetField Value
| Type | Description |
|---|---|
| bool |
Remarks
When enabled, the bone continuously rotates to point its forward axis toward the targetTransform. This creates realistic articulation for suspension arms and linkages that need to track wheel or component movement.
The rotation uses the vehicle's up vector to maintain proper alignment relative to the vehicle body during turning and rolling.
stretchToTarget
Scale the bone along its Z-axis to maintain connection with the target.
Declaration
[Tooltip("Should the object be stretched between pivot and target?")]
public bool stretchToTargetField Value
| Type | Description |
|---|---|
| bool |
Remarks
When enabled, the bone's Z-axis scale is adjusted based on the distance to the targetTransform. This creates the appearance of stretching or compressing to maintain visual connection as the target moves.
Useful for: - Shock absorbers compressing and extending - Tie rods adjusting length during steering - Control arms adapting to suspension travel - Any cylindrical component connecting two moving points
The scale is calculated relative to the initial distance captured during Initialize().
targetTransform
The target transform that the bone should track or connect to.
Declaration
[Tooltip("The transform that represents the lookAtTarget and stretch target.")]
public Transform targetTransformField Value
| Type | Description |
|---|---|
| Transform |
Remarks
Primary target for bone animation. When lookAtTarget is enabled, the bone rotates to face this transform. When stretchToTarget is enabled, the bone scales to reach this transform.
Typically assigned to: - Wheel transforms for suspension arms - WheelController transforms for accurate positioning - Other bone transforms for complex linkages - Custom animation targets for special effects
targetTransformB
Second target transform for double-sided bone positioning.
Declaration
[Tooltip(" Second target. Object will be stretched positioned between targetTransform and targetTransformB if doubleSided is\r\n true.")]
public Transform targetTransformBField Value
| Type | Description |
|---|---|
| Transform |
Remarks
Only used when doubleSided is enabled. The bone will be positioned at the midpoint between targetTransform and targetTransformB.
Common usage: - Axles spanning between left and right wheels - Anti-roll bars connecting opposite suspension points - Cross-members linking both sides of the vehicle
thisTransform
The transform representing this bone in the vehicle rig.
Declaration
[Tooltip("The transform that represents the bone.")]
public Transform thisTransformField Value
| Type | Description |
|---|---|
| Transform |
Remarks
The transform that will be animated by this bone definition. This should be a child transform of the vehicle model, typically part of a rigged mesh hierarchy exported from 3D modeling software.
This transform's position, rotation, and scale will be modified each frame based on the bone's configuration and target positions.
Methods
Initialize()
Initializes the bone by caching initial distances and scales.
Declaration
public void Initialize()Remarks
Called once during module initialization to establish reference values. Stores the initial distance between bone and target, and the initial Z scale. These values are used as references for the stretching calculation.
Must be called before Update() to ensure proper stretching behavior. The initial configuration represents the "rest" or "neutral" position of the bone.
Update(Vector3)
Updates the bone transform based on target position and configuration.
Declaration
public void Update(Vector3 up)Parameters
| Type | Name | Description |
|---|---|---|
| Vector3 | up | Vehicle up direction for LookAt alignment. |
Remarks
Called every frame to update the bone's position, rotation, and scale. The update behavior depends on the configured options:
- If doubleSided is true: Centers between two targets - If lookAtTarget is true: Rotates to face the target - If stretchToTarget is true: Scales to maintain connection
The vehicle's up vector ensures proper alignment relative to the vehicle body, maintaining correct orientation during vehicle rotation.