VPinJoint¶

Qualified name: manim\_pymunk.constraints.VPinJoint

class VPinJoint(a_mob, b_mob, anchor_a_local=array([0., 0., 0.]), anchor_b_local=array([0., 0., 0.]), distance=None, anchor_a_appearance=Dot, anchor_b_appearance=Dot, connect_line_class=None, connect_line_config={'color': ManimColor('#F7D96F'), 'stroke_width': 2}, **kwargs)[source]¶

Bases: VConstraint

A pin joint keeps a fixed distance between two anchor points on two rigid bodies. It acts like a solid, weightless rod connecting two points, allowing them to rotate freely around the anchors while maintaining the specified distance.

Parameters¶

a_mob: The first Mobject to be connected.
b_mob: The second Mobject to be connected.
anchor_a_local: The local anchor point on a_mob where the pin is attached, relative to the Mobject’s center.
anchor_b_local: The local anchor point on b_mob where the pin is attached, relative to the Mobject’s center.
distance: The fixed distance to maintain between the two anchors. If None, it is automatically calculated as the initial distance between anchors.
anchor_a_appearance: The Mobject used to visually represent the anchor point on a_mob (e.g., a red Dot).
anchor_b_appearance: The Mobject used to visually represent the anchor point on b_mob (e.g., a red Dot).
connect_line_class: The class used to draw the connecting rod (e.g., Line). Defaults to None for no visible connection.
connect_line_config: A dictionary defining the visual style of the connecting line, such as color and stroke_width.

Examples¶

Example: VPinJointExample ¶

from manim import *

from manim_pymunk import *

class VPinJointExample(SpaceScene):
    def construct(self):

        static_dot = Dot(ORIGIN)
        square = Square().move_to(static_dot)
        square2 = Square().move_to(static_dot.get_center() + UP * 2).scale(0.5)

        constraints = [
            VPinJoint(static_dot, square),
            VPinJoint(
                square,
                square2,
                anchor_a_local=square.get_corner(UR) - square.get_center(),
                distance=2,
                connect_line_class=Line,
            ),
        ]

        self.add_static_body(static_dot)
        self.add_dynamic_body(square, square2, angular_velocity=PI * 2)
        self.add_shapes_filter(static_dot, square, square2, group=2)
        self.add_constraints(*constraints)
        self.wait(3)

from manim_pymunk import *

class VPinJointExample(SpaceScene):
    def construct(self):

        static_dot = Dot(ORIGIN)
        square = Square().move_to(static_dot)
        square2 = Square().move_to(static_dot.get_center() + UP * 2).scale(0.5)

        constraints = [
            VPinJoint(static_dot, square),
            VPinJoint(
                square,
                square2,
                anchor_a_local=square.get_corner(UR) - square.get_center(),
                distance=2,
                connect_line_class=Line,
            ),
        ]

        self.add_static_body(static_dot)
        self.add_dynamic_body(square, square2, angular_velocity=PI * 2)
        self.add_shapes_filter(static_dot, square, square2, 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, anchor_a_local=array([0., 0., 0.]), anchor_b_local=array([0., 0., 0.]), distance=None, anchor_a_appearance=Dot, anchor_b_appearance=Dot, 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)
anchor_a_local (list[float, float, float])
anchor_b_local (list[float, float, float])
distance (float | None)
anchor_a_appearance (Mobject)
anchor_b_appearance (Mobject)
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¶

constraint: PinJoint | 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)
anchor_a_local (list[float, float, float])
anchor_b_local (list[float, float, float])
distance (float | None)
anchor_a_appearance (Mobject)
anchor_b_appearance (Mobject)
connect_line_class (Line | None)
connect_line_config (dict)