physics Package¶

`base` Module¶

class Body(mass=None, density=None, pos=None, rot=None, *args, **kwargs)[source]¶

Bases: object

attach_geom(geom)[source]¶

calc_potential_energy(gravity)[source]¶

Calculate the potential energy of the body due to its position (x) and the gravitational acceleration (g).

$E_p &= m \cdot g \cdot h = - m \cdot g^\top x$

Parameters:	gravity (tuple of 3 floats) – gravitational acceleration vector
Returns:	potential energy
Return type:	float

calc_rotation_kinetic_energy()[source]¶

Calculate the kinetic energy of the body due to rotational movement.

$E_{kr} = \frac{1}{2} I \omega^2 = \frac{1}{2} \omega^\top \mathbf{I} \omega$

Returns:	kinetic energy
Return type:	float

calc_translation_kinetic_energy()[source]¶

Calculate the kinetic energy of the body due to translational movement.

$E_{kt} = \frac{1}{2} m v^2 = \frac{1}{2} m \cdot v^\top v$

Returns:	kinetic energy
Return type:	float

get_angular_velocity()[source]¶

get_attached_geom()[source]¶

get_center_of_gravity()[source]¶

get_inertia_tensor()[source]¶

get_linear_velocity()[source]¶

get_mass()[source]¶

get_position()[source]¶

Get the position of the body.

Returns:	position
Return type:	3-sequence of floats

get_rotation()[source]¶

Get the orientation of the body.

Returns:	rotation matrix
Return type:	9-sequence of floats

get_saved_velocities()[source]¶: Return last saved velocities (linear and angular).

inner_object¶

save_velocities()[source]¶: Retrieve the actual velocities (linear and angular) of the body and save them.

set_position(pos)[source]¶

Set the position of the body.

Sends signals.BODY_PRE_SET_POSITION and signals.BODY_POST_SET_POSITION.

Parameters:	pos (3-sequence of floats) – position

set_rotation(rot)[source]¶

Set the orientation of the body.

Sends signals.BODY_PRE_SET_ROTATION and signals.BODY_POST_SET_ROTATION.

Parameters:	rot (9-sequence of floats) – rotation matrix

class Box(size, *args, **kwargs)[source]¶

Bases: ars.model.physics.base.Body

size¶

class Capsule(length, radius, *args, **kwargs)[source]¶

Bases: ars.model.physics.base.Body

length¶

radius¶

class Cone(height, radius, *args, **kwargs)[source]¶

Bases: ars.model.physics.base.Body

height¶

radius¶

class Cylinder(length, radius, *args, **kwargs)[source]¶

Bases: ars.model.physics.base.Body

length¶

radius¶

class Engine[source]¶

Bases: object

world_class = None¶

class Sphere(radius, *args, **kwargs)[source]¶

Bases: ars.model.physics.base.Body

radius¶

class World(gravity, *args, **kwargs)[source]¶

Bases: object

gravity¶

inner_object¶

step(time_step)[source]¶: Subclasses implementing this method must send the corresponding signals, defined in ars.model.physics.signals.

`ode_adapter` Module¶

Classes and functions to interface the ODE physics engine with the API defined in physics.

class Body(world, space, mass=None, density=None, *args, **kwargs)[source]¶

Bases: object

Abstract class, sort of equivalent to ode.Body.

Constructor.

Parameters:	world (`base.World`) – space (`collision.base.Space`) – mass (float or None) – density (float or None) –

get_angular_velocity()[source]¶

get_center_of_gravity()[source]¶

get_inertia_tensor()[source]¶

get_linear_velocity()[source]¶

get_mass()[source]¶

get_position()[source]¶

Get the position of the body.

Returns:	position
Return type:	3-sequence of floats

get_rotation()[source]¶

Get the orientation of the body.

Returns:	rotation matrix
Return type:	9-sequence of floats

set_position(pos)[source]¶

Set the position of the body.

Sends signals.BODY_PRE_SET_POSITION and signals.BODY_POST_SET_POSITION.

Parameters:	pos (3-sequence of floats) – position

set_rotation(rot)[source]¶

Set the orientation of the body.

Sends signals.BODY_PRE_SET_ROTATION and signals.BODY_POST_SET_ROTATION.

Parameters:	rot (9-sequence of floats) – rotation matrix

class Box(world, space, size, mass=None, density=None)[source]¶: Bases: ars.model.physics.ode_adapter.Body, ars.model.physics.base.Box

class Capsule(world, space, length, radius, mass=None, density=None)[source]¶

Bases: ars.model.physics.ode_adapter.Body, ars.model.physics.base.Capsule

create capsule body (aligned along the z-axis so that it matches the Geom created below, which is aligned along the Z-axis by default)

class Cylinder(world, space, length, radius, mass=None, density=None)[source]¶

Bases: ars.model.physics.ode_adapter.Body, ars.model.physics.base.Cylinder

create cylinder body (aligned along the z-axis so that it matches the Geom created below, which is aligned along the Z-axis by default)

class Engine[source]¶

Bases: ars.model.physics.base.Engine

Adapter to the ODE physics engine

world_class¶: alias of World

class Sphere(world, space, radius, mass=None, density=None)[source]¶: Bases: ars.model.physics.ode_adapter.Body, ars.model.physics.base.Sphere

class World(gravity=(0.0, -9.81, 0.0), ERP=0.2, CFM=1e-10, *args, **kwargs)[source]¶

Bases: ars.model.physics.base.World

Adapter to ode.World.

`ode_objects_factories` Module¶

ODE objects factories i.e. functions that create ODE objects.

create_ode_box(world, size, mass=None, density=None)[source]¶

Create an ODE body with box-like mass parameters.

Parameters:	world (`ode.World`) – size (3-sequence of floats) – mass (float or None) – density (float or None) –
Returns:	box body
Return type:	`ode.Body`

create_ode_capsule(world, length, radius, mass=None, density=None)[source]¶

Create an ODE body with capsule-like mass parameters.

Parameters:	world (`ode.World`) – length (float) – radius (float) – mass (float or None) – density (float or None) –
Returns:	capsule body
Return type:	`ode.Body`

create_ode_cylinder(world, length, radius, mass=None, density=None)[source]¶

Create an ODE body with cylinder-like mass parameters.

Parameters:	world (`ode.World`) – length (float) – radius (float) – mass (float or None) – density (float or None) –
Returns:	cylinder body
Return type:	`ode.Body`

create_ode_sphere(world, radius, mass=None, density=None)[source]¶

Create an ODE body with sphere-like mass parameters.

Parameters:	world (`ode.World`) – radius (float) – mass (float or None) – density (float or None) –
Returns:	sphere body
Return type:	`ode.Body`

create_ode_world(gravity=(0.0, -9.81, 0.0), ERP=0.8, CFM=1e-10)[source]¶

Create an ODE world object.

Parameters:	gravity (3-sequence of floats) – gravity acceleration vector ERP (float) – Error Reduction Parameter CFM (float) – Constraint Force Mixing
Returns:	world
Return type:	`ode.World`

`signals` Module¶

This module contains string values defining different signals related to the ars.model.physics package.

physics Package¶

base Module¶

ode_adapter Module¶

ode_objects_factories Module¶

signals Module¶

`base` Module¶

`ode_adapter` Module¶

`ode_objects_factories` Module¶

`signals` Module¶