Wheel Joint

The wheel joint can be used to simulate wheels on vehicles. More...

Collaboration diagram for Wheel Joint:

Data Structures
struct	b2WheelJointDef
	Wheel joint definition. More...

Functions
b2JointId	b2CreateWheelJoint (b2WorldId worldId, const b2WheelJointDef *def)
	Create a wheel joint.
void	b2WheelJoint_EnableSpring (b2JointId jointId, bool enableSpring)
	Enable/disable the wheel joint spring.
bool	b2WheelJoint_IsSpringEnabled (b2JointId jointId)
	Is the wheel joint spring enabled?
void	b2WheelJoint_SetSpringHertz (b2JointId jointId, float hertz)
	Set the wheel joint stiffness in Hertz.
float	b2WheelJoint_GetSpringHertz (b2JointId jointId)
	Get the wheel joint stiffness in Hertz.
void	b2WheelJoint_SetSpringDampingRatio (b2JointId jointId, float dampingRatio)
	Set the wheel joint damping ratio, non-dimensional.
float	b2WheelJoint_GetSpringDampingRatio (b2JointId jointId)
	Get the wheel joint damping ratio, non-dimensional.
void	b2WheelJoint_EnableLimit (b2JointId jointId, bool enableLimit)
	Enable/disable the wheel joint limit.
bool	b2WheelJoint_IsLimitEnabled (b2JointId jointId)
	Is the wheel joint limit enabled?
float	b2WheelJoint_GetLowerLimit (b2JointId jointId)
	Get the wheel joint lower limit.
float	b2WheelJoint_GetUpperLimit (b2JointId jointId)
	Get the wheel joint upper limit.
void	b2WheelJoint_SetLimits (b2JointId jointId, float lower, float upper)
	Set the wheel joint limits.
void	b2WheelJoint_EnableMotor (b2JointId jointId, bool enableMotor)
	Enable/disable the wheel joint motor.
bool	b2WheelJoint_IsMotorEnabled (b2JointId jointId)
	Is the wheel joint motor enabled?
void	b2WheelJoint_SetMotorSpeed (b2JointId jointId, float motorSpeed)
	Set the wheel joint motor speed in radians per second.
float	b2WheelJoint_GetMotorSpeed (b2JointId jointId)
	Get the wheel joint motor speed in radians per second.
void	b2WheelJoint_SetMaxMotorTorque (b2JointId jointId, float torque)
	Set the wheel joint maximum motor torque, typically in newton-meters.
float	b2WheelJoint_GetMaxMotorTorque (b2JointId jointId)
	Get the wheel joint maximum motor torque, typically in newton-meters.
float	b2WheelJoint_GetMotorTorque (b2JointId jointId)
	Get the wheel joint current motor torque, typically in newton-meters.
b2WheelJointDef	b2DefaultWheelJointDef (void)
	Use this to initialize your joint definition.

Detailed Description

The wheel joint can be used to simulate wheels on vehicles.

The wheel joint restricts body B to move along a local axis in body A. Body B is free to rotate. Supports a linear spring, linear limits, and a rotational motor.

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Data Structure Documentation

b2WheelJointDef

struct b2WheelJointDef

Wheel joint definition.

This requires defining a line of motion using an axis and an anchor point. The definition uses local anchor points and a local axis so that the initial configuration can violate the constraint slightly. The joint translation is zero when the local anchor points coincide in world space.

Collaboration diagram for b2WheelJointDef:

Data Fields
b2BodyId	bodyIdA	The first attached body.
b2BodyId	bodyIdB	The second attached body.
bool	collideConnected	Set this flag to true if the attached bodies should collide.
float	dampingRatio	Spring damping ratio, non-dimensional.
bool	enableLimit	Enable/disable the joint linear limit.
bool	enableMotor	Enable/disable the joint rotational motor.
bool	enableSpring	Enable a linear spring along the local axis.
float	hertz	Spring stiffness in Hertz.
int32_t	internalValue	Used internally to detect a valid definition. DO NOT SET.
b2Vec2	localAnchorA	The local anchor point relative to bodyA's origin.
b2Vec2	localAnchorB	The local anchor point relative to bodyB's origin.
b2Vec2	localAxisA	The local translation unit axis in bodyA.
float	lowerTranslation	The lower translation limit.
float	maxMotorTorque	The maximum motor torque, typically in newton-meters.
float	motorSpeed	The desired motor speed in radians per second.
float	upperTranslation	The upper translation limit.
void *	userData	User data pointer.

Function Documentation

b2CreateWheelJoint()

b2JointId b2CreateWheelJoint	(	b2WorldId	worldId,
		const b2WheelJointDef *	def )

Create a wheel joint.

See also

b2WheelJointDef for details