Class Joint

A base class for all Joint types. Joints constrain how two rigidbodies move relative to one another (for example a door hinge). One of the bodies in the joint must always be movable (non-kinematic and non-static).

Joint constraint is created between the parent physic actor (rigidbody, character controller, etc.) and the specified target actor.

Joint
Joint
Joint
Joint
Joint
Assembly: FlaxEngine.dll
File: Engine/Physics/Joints/Joint.h
Syntax
public class Joint : public Actor, public IPhysicsDebug

Fields

_breakForce

Declaration
protected float _breakForce
Field Value
float

_breakTorque

Declaration
protected float _breakTorque
Field Value
float

_enableAutoAnchor

Declaration
protected bool _enableAutoAnchor = false
Field Value
bool

_enableCollision

Declaration
protected bool _enableCollision = true
Field Value
bool

_joint

Declaration
protected void* _joint
Field Value
void

_targetAnchor

Declaration
protected Vector3 _targetAnchor
Field Value
Vector3

_targetAnchorRotation

Declaration
protected Quaternion _targetAnchorRotation
Field Value
Quaternion

ImplementPhysicsDebug

Declaration
protected ImplementPhysicsDebug

JointBreak

Occurs when a joint gets broken during simulation.

Declaration
public Action JointBreak
Field Value
Action

Target

The target actor for the joint. It has to be IPhysicsActor type (eg. RigidBody or CharacterController).

Declaration
public ScriptingObjectReference<Actor> Target
Field Value
ScriptingObjectReference<Actor>

Methods

BeginPlay(SceneBeginData* data)

Called when adding object to the game.

Declaration
protected virtual void BeginPlay(SceneBeginData* data) override
Parameters
SceneBeginData data

The initialization data (e.g. used to collect joints to link after begin).
Overrides

Create()

Creates native join object.

Declaration
public void Create()

CreateJoint(const struct PhysicsJointDesc& desc)

Declaration
protected virtual void* CreateJoint(const struct PhysicsJointDesc& desc) = 0
Parameters
struct PhysicsJointDesc desc

Returns
void

Deserialize(DeserializeStream& stream, ISerializeModifier* modifier)

Deserializes object from the input stream.

Declaration
public virtual void Deserialize(DeserializeStream& stream, ISerializeModifier* modifier) override
Parameters
DeserializeStream stream

The input stream.
ISerializeModifier modifier

The deserialization modifier object. Always valid.
Overrides

EndPlay()

Called when removing object from the game.

Declaration
protected virtual void EndPlay() override
Overrides

GetBreakForce()

Gets the break force. Determines the maximum force the joint can apply before breaking. Broken joints no longer participate in physics simulation.

Declaration
public float GetBreakForce() const
Returns
float

GetBreakTorque()

Gets the break torque. Determines the maximum torque the joint can apply before breaking. Broken joints no longer participate in physics simulation.

Declaration
public float GetBreakTorque() const
Returns
float

GetCurrentForce(Vector3& linear, Vector3& angular)

Gets the current force applied by the solver to maintain all constraints.

Declaration
public void GetCurrentForce(Vector3& linear, Vector3& angular) const
Parameters
Vector3 linear

The result linear force.
Vector3 angular

The result angular force.

GetEnableAutoAnchor()

Determines whether use automatic target anchor position and rotation based on the joint world-space frame (computed when creating joint).

Declaration
public bool GetEnableAutoAnchor() const
Returns
bool

GetEnableCollision()

Determines whether collision between the two bodies managed by the joint are enabled.

Declaration
public bool GetEnableCollision() const
Returns
bool

GetPhysicsImpl()

Gets the native physics backend object.

Declaration
public void* GetPhysicsImpl() const
Returns
void

GetTargetAnchor()

Gets the target anchor.

This is the relative pose which locates the joint frame relative to the target actor.

Declaration
public Vector3 GetTargetAnchor() const
Returns
Vector3

GetTargetAnchorRotation()

Gets the target anchor rotation.

This is the relative pose rotation which locates the joint frame relative to the target actor.

Declaration
public Quaternion GetTargetAnchorRotation() const
Returns
Quaternion

GetTargetOrientation()

Declaration
protected Quaternion GetTargetOrientation() const
Returns
Quaternion

GetTargetPosition()

Declaration
protected Vector3 GetTargetPosition() const
Returns
Vector3

OnActiveInTreeChanged()

Called when actor active in tree state gets changed.

Declaration
protected virtual void OnActiveInTreeChanged() override
Overrides

OnDebugDrawSelected()

Draws debug shapes for the selected actor and all child scripts.

Declaration
public virtual void OnDebugDrawSelected() override
Overrides

OnDisable()

Called when actor gets removed from game systems. Occurs on EndPlay event or when actor gets inactivated in hierarchy. Use this event to unregister object from other game system (eg. audio).

Declaration
protected virtual void OnDisable() override
Overrides

OnEnable()

Called when actor gets added to game systems. Occurs on BeginPlay event or when actor gets activated in hierarchy. Use this event to register object to other game system (eg. audio).

Declaration
protected virtual void OnEnable() override
Overrides

OnJointBreak()

Called by the physics system when joint gets broken.

Declaration
public virtual void OnJointBreak()

OnParentChanged()

Called when actor parent gets changed.

Declaration
protected virtual void OnParentChanged() override
Overrides

OnTransformChanged()

Called when actor transform gets changed.

Declaration
protected virtual void OnTransformChanged() override
Overrides

Serialize(SerializeStream& stream, const void* otherObj)

Serializes object to the output stream compared to the values of the other object instance (eg. default class object). If other object is null then serialize all properties.

Declaration
public virtual void Serialize(SerializeStream& stream, const void* otherObj) override
Parameters
SerializeStream stream

The output stream.
void otherObj

The instance of the object to compare with and serialize only the modified properties. If null, then serialize all properties.
Overrides

SetBreakForce(float value)

Sets the break force. Determines the maximum force the joint can apply before breaking. Broken joints no longer participate in physics simulation.

Declaration
public void SetBreakForce(float value)
Parameters
float value

SetBreakTorque(float value)

Sets the break torque. Determines the maximum torque the joint can apply before breaking. Broken joints no longer participate in physics simulation.

Declaration
public void SetBreakTorque(float value)
Parameters
float value

SetEnableAutoAnchor(bool value)

Determines whether use automatic target anchor position and rotation based on the joint world-space frame (computed when creating joint).

Declaration
public void SetEnableAutoAnchor(bool value)
Parameters
bool value

SetEnableCollision(bool value)

Determines whether collision between the two bodies managed by the joint are enabled.

Declaration
public void SetEnableCollision(bool value)
Parameters
bool value

SetJointLocation(const Vector3& location)

Sets the location of the joint by automatically computing local position and target anchor to place a joint at the given location (world-space).

Use this utility to automatically place joint at the given location after setting up joint parent and target.

Declaration
public void SetJointLocation(const Vector3& location)
Parameters
Vector3 location

The joint location to set (world-space).

SetJointOrientation(const Quaternion& orientation)

Sets the orientation of the joint by automatically computing local orientation and target anchor orientation to orient a joint at the given rotation (world-space).

Use this utility to automatically rotate joint at the given location after setting up joint parent and target.

Declaration
public void SetJointOrientation(const Quaternion& orientation)
Parameters
Quaternion orientation

The joint orientation to set (world-space).

SetTargetAnchor(const Vector3& value)

Sets the target anchor.

This is the relative pose which locates the joint frame relative to the target actor.

Declaration
public void SetTargetAnchor(const Vector3& value)
Parameters
Vector3 value

SetTargetAnchorRotation(const Quaternion& value)

Sets the target anchor rotation.

This is the relative pose rotation which locates the joint frame relative to the target actor.

Declaration
public void SetTargetAnchorRotation(const Quaternion& value)
Parameters
Quaternion value

See Also