VRatchetJoint¶

Qualified name: manim\_pymunk.constraints.VRatchetJoint

class VRatchetJoint(a_mob, b_mob, phase=0.0, ratchet=1.5707963267948966, indicator_line_class=<class 'manim.mobject.geometry.line.Arrow'>, indicator_line_config={'color': ManimColor('#58C4DD'), 'stroke_width': 2}, indicator_line_length=0.4, connect_line_class=None, connect_line_config={'color': ManimColor('#F7D96F'), 'stroke_width': 2}, **kwargs)[source]¶

Bases: VConstraint

Initializes a Ratchet Joint constraint between two Mobjects.

A Ratchet Joint acts like a rotary pawl, allowing relative rotation only in discrete increments and in one direction. It is perfect for simulating winding mechanisms, clockwork, or unidirectional gears.

Parameters¶

a_mob: The first Mobject (the base or reference body).
b_mob: The second Mobject (the body subject to the ratchet effect).
phase: The initial angular offset of the ratchet teeth.
ratchet: The angular distance between each “tooth” (in radians). For example, PI/2 means the joint locks at every 90-degree interval.
indicator_line_class: The Manim class used to visualize the current rotation or ratchet direction.
indicator_line_config: Configuration dictionary for the styling of the indicator arrow.
indicator_line_length: The visual length of the indicator line.
connect_line_class: The Manim class used to draw a line between the centers of the two objects. Set to None to disable.
connect_line_config: Configuration dictionary for the styling of the connection line.

Examples¶

Example: VRatchetJointExample ¶

from manim import *

from manim_pymunk import *

class VRatchetJointExample(SpaceScene):
    def construct(self):
        floor = Line(LEFT * 10, RIGHT * 10).shift(DOWN * 2)

        static_dot1 = Dot(UP * 2)
        static_dot2 = Dot(UP * 2 + RIGHT * 4)

        square_1 = Square().move_to(static_dot1)
        square_2 = Square().move_to(static_dot2)

        constraints = [
            VRatchetJoint(
                square_1,
                square_2,
                phase=PI / 4,
                ratchet=PI,
            ),
            VPinJoint(static_dot1, square_1),
            VPinJoint(static_dot2, square_2),
        ]

        self.add_static_body(floor, static_dot1, static_dot2)
        self.add_dynamic_body(square_1, angular_velocity=PI * 2)
        self.add_dynamic_body(square_2)

        self.add_shapes_filter(static_dot1, static_dot2, square_1, square_2, group=2)
        self.add_constraints(*constraints)
        self.wait(3)

from manim_pymunk import *

class VRatchetJointExample(SpaceScene):
    def construct(self):
        floor = Line(LEFT * 10, RIGHT * 10).shift(DOWN * 2)

        static_dot1 = Dot(UP * 2)
        static_dot2 = Dot(UP * 2 + RIGHT * 4)

        square_1 = Square().move_to(static_dot1)
        square_2 = Square().move_to(static_dot2)

        constraints = [
            VRatchetJoint(
                square_1,
                square_2,
                phase=PI / 4,
                ratchet=PI,
            ),
            VPinJoint(static_dot1, square_1),
            VPinJoint(static_dot2, square_2),
        ]

        self.add_static_body(floor, static_dot1, static_dot2)
        self.add_dynamic_body(square_1, angular_velocity=PI * 2)
        self.add_dynamic_body(square_2)

        self.add_shapes_filter(static_dot1, static_dot2, square_1, square_2, group=2)
        self.add_constraints(*constraints)
        self.wait(3)

Methods

`install`	Installs physical constraints into the Pymunk physical space.
`mob_updater`	Visual control updater

Attributes

`always`	Call a method on a mobject every frame.
`animate`	Used to animate the application of any method of `self`.
`animation_overrides`
`color`
`depth`	The depth of the mobject.
`fill_color`	If there are multiple colors (for gradient) this returns the first one
`height`	The height of the mobject.
`n_points_per_curve`
`sheen_factor`
`stroke_color`
`width`	The width of the mobject.

__check_data()¶: Verify the validity of constraint parameters.

_abc_impl = <_abc._abc_data object>¶

_bezier_t_values: npt.NDArray[float]¶

_original__init__(a_mob, b_mob, phase=0.0, ratchet=1.5707963267948966, indicator_line_class=<class 'manim.mobject.geometry.line.Arrow'>, indicator_line_config={'color': ManimColor('#58C4DD'), 'stroke_width': 2}, indicator_line_length=0.4, connect_line_class=None, connect_line_config={'color': ManimColor('#F7D96F'), 'stroke_width': 2}, **kwargs)¶

Initialize self. See help(type(self)) for accurate signature.

Parameters:

a_mob (Mobject)
b_mob (Mobject)
phase (float)
ratchet (float)
indicator_line_class (Line | None)
indicator_line_config (dict)
connect_line_class (Line | None)
connect_line_config (dict)

animation_overrides = {}¶

background_image: Image | str | None¶

background_stroke_color: ManimColor¶

background_stroke_opacity: float¶

background_stroke_width: float¶

cap_style: CapStyleType¶

close_new_points: bool¶

connect_line: VMobject | None¶

constraint: RatchetJoint | None¶

install(space)[source]¶

Installs physical constraints into the Pymunk physical space. This method should be overridden by subclasses to implement the following:

Create Pymunk constraint objects
Initialize the vision component
Add constraints to the physical space
Bind an updater to keep the vision synchronized.

Parameters:: space (Space)

joint_type: LineJointType¶

make_smooth_after_applying_functions: bool¶

mob_updater(mob, dt)[source]¶: Visual control updater

n_points_per_cubic_curve: int¶

pre_function_handle_to_anchor_scale_factor: float¶

shade_in_3d: bool¶

submobjects: list[VMobject]¶

tolerance_for_point_equality: float¶

Parameters:

a_mob (Mobject)
b_mob (Mobject)
phase (float)
ratchet (float)
indicator_line_class (Line | None)
indicator_line_config (dict)
connect_line_class (Line | None)
connect_line_config (dict)