Box2D.RevoluteJointDef Class Reference

Revolute joint definition
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Public Member Functions
	RevoluteJointDef (Body bodyA, Body bodyB, Vec2 anchorA, Vec2 anchorB, float referenceAngle=0.0f, bool enableSpring=false, float hertz=0.0f, float dampingRatio=0.0f, bool enableLimit=false, float lowerAngle=0.0f, float upperAngle=0.0f, bool enableMotor=false, float maxMotorTorque=0.0f, float motorSpeed=0.0f, bool collideConnected=false, object? userData=null)
	Construct a revolute joint definition with the supplied values.
	RevoluteJointDef ()
	Construct a revolute joint definition with the default values.

Properties
ref Body	BodyA [get]
	The first attached body.
ref Body	BodyB [get]
	The second attached body.
ref Vec2	LocalAnchorA [get]
	The local anchor point relative to bodyA's origin.
ref Vec2	LocalAnchorB [get]
	The local anchor point relative to bodyB's origin.
ref float	ReferenceAngle [get]
	The bodyB angle minus bodyA angle in the reference state (radians). This defines the zero angle for the joint limit.
bool	EnableSpring [get, set]
	Enable a rotational spring on the revolute hinge axis.
ref float	Hertz [get]
	The spring stiffness Hertz, cycles per second.
ref float	DampingRatio [get]
	The spring damping ratio, non-dimensional.
bool	EnableLimit [get, set]
	A flag to enable joint limits.
ref float	LowerAngle [get]
	The lower angle for the joint limit in radians. Minimum of -0.95*pi radians.
ref float	UpperAngle [get]
	The upper angle for the joint limit in radians. Maximum of 0.95*pi radians.
bool	EnableMotor [get, set]
	A flag to enable the joint motor.
ref float	MaxMotorTorque [get]
	The maximum motor torque, typically in newton-meters.
ref float	MotorSpeed [get]
	The desired motor speed in radians per second.
ref float	DrawSize [get]
	Scale the debug draw.
bool	CollideConnected [get, set]
	Set this flag to true if the attached bodies should collide.
object?	UserData [get, set]
	User data.

Detailed Description

Revolute joint definition

This requires defining an anchor point where the bodies are joined.
The definition uses local anchor points so that the initial configuration can violate the constraint slightly. You also need to specify the initial relative angle for joint limits. This helps when saving and loading a game.
The local anchor points are measured from the body's origin rather than the center of mass because:

1. you might not know where the center of mass will be
   
2. if you add/remove shapes from a body and recompute the mass, the joints will be broken

Constructor & Destructor Documentation

RevoluteJointDef()

Box2D.RevoluteJointDef.RevoluteJointDef ( Body  bodyA, Body  bodyB, Vec2  anchorA, Vec2  anchorB, float  referenceAngle = 0::0f, bool  enableSpring = false, float  hertz = 0::0f, float  dampingRatio = 0::0f, bool  enableLimit = false, float  lowerAngle = 0::0f, float  upperAngle = 0::0f, bool  enableMotor = false, float  maxMotorTorque = 0::0f, float  motorSpeed = 0::0f, bool  collideConnected = false, object?  userData = null  )

inline

Construct a revolute joint definition with the supplied values.

Parameters

bodyA	The first attached body
bodyB	The second attached body
anchorA	The local anchor point relative to bodyA's origin
anchorB	The local anchor point relative to bodyB's origin
referenceAngle	The bodyB angle minus bodyA angle in the reference state (radians)
enableSpring	Enable a rotational spring on the revolute hinge axis
hertz	The spring stiffness Hertz, cycles per second
dampingRatio	The spring damping ratio, non-dimensional
enableLimit	A flag to enable joint limits
lowerAngle	The lower angle for the joint limit in radians
upperAngle	The upper angle for the joint limit in radians
enableMotor	A flag to enable the joint motor
maxMotorTorque	The maximum motor torque, typically in newton-meters
motorSpeed	The desired motor speed in radians per second
collideConnected	Set this flag to true if the attached bodies should collide
userData	User data

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The documentation for this class was generated from the following file:

• src/Box2DBindings/Defs/RevoluteJointDef.cs