Struct RevoluteJoint 

#[repr(transparent)]
pub struct RevoluteJoint {
    pub data: GenericJoint,
}

A hinge joint that allows rotation around one axis (like a door hinge or wheel axle).

Revolute joints lock all movement except rotation around a single axis. Use for:

• Door hinges
• Wheels and gears
• Joints in robotic arms
• Pendulums
• Any rotating connection

You can optionally add:

• Limits: Restrict rotation to a range (e.g., door that only opens 90°)
• Motor: Powered rotation with target velocity or position

In 2D there’s only one rotation axis (Z). In 3D you specify which axis (X, Y, or Z).

Fields

data: GenericJoint

The underlying joint data.

Implementations

impl RevoluteJoint

pub fn new(axis: UnitVector<f32>) -> Self

Creates a new revolute joint allowing only relative rotations along the specified axis.

This axis is expressed in the local-space of both rigid-bodies.

pub fn data(&self) -> &GenericJoint

The underlying generic joint.

pub fn contacts_enabled(&self) -> bool

Are contacts between the attached rigid-bodies enabled?

pub fn set_contacts_enabled(&mut self, enabled: bool) -> &mut Self

Sets whether contacts between the attached rigid-bodies are enabled.

pub fn local_anchor1(&self) -> Point<f32>

The joint’s anchor, expressed in the local-space of the first rigid-body.

pub fn set_local_anchor1(&mut self, anchor1: Point<f32>) -> &mut Self

Sets the joint’s anchor, expressed in the local-space of the first rigid-body.

pub fn local_anchor2(&self) -> Point<f32>

The joint’s anchor, expressed in the local-space of the second rigid-body.

pub fn set_local_anchor2(&mut self, anchor2: Point<f32>) -> &mut Self

Sets the joint’s anchor, expressed in the local-space of the second rigid-body.

pub fn angle(&self, rb_rot1: &Rotation<f32>, rb_rot2: &Rotation<f32>) -> f32

The angle along the free degree of freedom of this revolute joint in [-π, π].

Parameters

• rb_rot1: the rotation of the first rigid-body attached to this revolute joint.
• rb_rot2: the rotation of the second rigid-body attached to this revolute joint.

pub fn motor(&self) -> Option<&JointMotor>

The motor affecting the joint’s rotational degree of freedom.

pub fn set_motor_model(&mut self, model: MotorModel) -> &mut Self

Set the spring-like model used by the motor to reach the desired target velocity and position.

pub fn set_motor_velocity(&mut self, target_vel: f32, factor: f32) -> &mut Self

Sets the motor’s target rotation speed.

Makes the joint spin at a desired velocity (like a powered motor or wheel).

Parameters

• target_vel - Desired angular velocity in radians/second
• factor - Motor strength (higher = stronger, approaches target faster)

pub fn set_motor_position( &mut self, target_pos: f32, stiffness: f32, damping: f32, ) -> &mut Self

Sets the motor’s target angle (position control).

Makes the joint rotate toward a specific angle using spring-like behavior.

Parameters

• target_pos - Desired angle in radians
• stiffness - How strongly to pull toward target (spring constant)
• damping - Resistance to motion (higher = less oscillation)

pub fn set_motor( &mut self, target_pos: f32, target_vel: f32, stiffness: f32, damping: f32, ) -> &mut Self

Configures both target angle and target velocity for the motor.

Combines position and velocity control for precise motor behavior.

pub fn set_motor_max_force(&mut self, max_force: f32) -> &mut Self

Sets the maximum torque the motor can apply.

Limits how strong the motor is. Without this, motors can apply infinite force.

pub fn limits(&self) -> Option<&JointLimits<f32>>

The rotation limits of this joint, if any.

Returns None if no limits are set (unlimited rotation).

pub fn set_limits(&mut self, limits: [f32; 2]) -> &mut Self

Restricts rotation to a specific angle range.

Parameters

• limits - [min_angle, max_angle] in radians

Example

// Door that opens 0° to 90°
joint.set_limits([0.0, std::f32::consts::PI / 2.0]);

pub fn softness(&self) -> SpringCoefficients<f32>

Gets the softness of this joint’s locked degrees of freedom.

pub fn set_softness(&mut self, softness: SpringCoefficients<f32>) -> &mut Self

Sets the softness of this joint’s locked degrees of freedom.

Trait Implementations

impl Clone for RevoluteJoint

fn clone(&self) -> RevoluteJoint

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RevoluteJoint

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for RevoluteJoint

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<RevoluteJoint> for GenericJoint

fn from(val: RevoluteJoint) -> GenericJoint

Converts to this type from the input type.

impl PartialEq for RevoluteJoint

fn eq(&self, other: &RevoluteJoint) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for RevoluteJoint

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for RevoluteJoint

impl StructuralPartialEq for RevoluteJoint