gale.physics.joint module

This file contains Joint, RevoluteJoint, and WheelJoint: constraints between two Bodies (a hinge, and a wheel-on-a-suspension-spring, respectively), wrapping one or more pymunk constraints without ever exposing pymunk itself. Created through World.create_revolute_joint/create_wheel_joint.

Author: Alejandro Mujica (aledrums@gmail.com)

class gale.physics.joint.Joint(pm_constraints)[source]

Bases: object

Base class for a constraint between two bodies. Created through World.create_revolute_joint/create_wheel_joint, never directly.

Parameters:

pm_constraints (List[Any])

destroy(pm_space)[source]

Internal — use World.destroy_joint instead.

Parameters:

pm_space (Any)

Return type:

None

class gale.physics.joint.RevoluteJoint(pivot, motor, limit, body_a, body_b)[source]

Bases: Joint

A pin joint: constrains two bodies to rotate around a shared point, optionally motorized and/or limited to an angle range.

Usage example:

joint = world.create_revolute_joint(anchor_body, arm, (100, 50)) joint.enable_motor = True joint.motor_speed = 2.0 joint.max_motor_torque = 500

joint.enable_limit = True joint.lower_angle = -0.5 joint.upper_angle = 0.5

Parameters:

  • pivot (Any)

  • motor (Any)

  • limit (Any)

  • body_a (Any)

  • body_b (Any)

property angle: float
property motor_speed: float
property max_motor_torque: float
property enable_motor: bool
property enable_limit: bool
property lower_angle: float
property upper_angle: float
class gale.physics.joint.WheelJoint(groove, spring, motor, mass, frequency, damping_ratio)[source]

Bases: Joint

A wheel with suspension: constrains a body to slide along an axis relative to another (the suspension, via a groove joint plus a damped spring), plus an unconstrained rotation (the wheel spinning), optionally motorized.

Usage example:

joint = world.create_wheel_joint(

chassis, wheel, wheel.position, frequencyHz=4, dampingRatio=0.7

) joint.enable_motor = True joint.motor_speed = -10 # drive forward joint.max_motor_torque = 800

Parameters:

  • groove (Any)

  • spring (Any)

  • motor (Any)

  • mass (float)

  • frequency (float)

  • damping_ratio (float)

property motor_speed: float
property max_motor_torque: float
property enable_motor: bool
property frequency: float
property damping_ratio: float