Blender

This example show how to create a blender with Box2D

Once Loop Reflect

/home/runner/.local/lib/python3.10/site-packages/b2d/testbed/backend/matplotlib_gif_gui/matplotlib_gif_gui.py:52: UserWarning: You passed in an explicit save_count=240 which is being ignored in favor of frames=240.
  self.ani = animation.FuncAnimation(

from b2d.testbed import TestbedBase
import random
import numpy
import b2d


class Blender(TestbedBase):

    name = "blender"

    def __init__(self, settings=None):
        super(Blender, self).__init__(settings=settings)
        dimensions = [30, 30]

        # the outer box
        box_shape = b2d.ChainShape()
        box_shape.create_loop(
            [
                (0, 0),
                (0, dimensions[1]),
                (dimensions[0], dimensions[1]),
                (dimensions[0], 0),
            ]
        )
        box = self.world.create_static_body(
            position=(0, 0), fixtures=b2d.fixture_def(shape=box_shape, friction=0)
        )

        for i in range(20):
            circle = self.world.create_dynamic_body(
                position=(dimensions[0] / 2 + random.random(), 1 + random.random()),
                fixtures=b2d.fixture_def(
                    density=1.0, shape=b2d.circle_shape(radius=1.0), restitution=1
                ),
                angular_damping=0,
                linear_damping=0,
            )

        body_a = self.world.create_static_body(
            position=(dimensions[0] / 2, dimensions[1] / 2)
        )
        l = 7.2
        body_b = self.world.create_dynamic_body(
            position=(dimensions[0] / 2, dimensions[1] / 2),
            shape=b2d.polygon_shape(box=[0.4, l]),
            density=1,
            angular_damping=0,
            linear_damping=0,
        )

        joint = self.world.create_revolute_joint(
            body_a=body_a,
            body_b=body_b,
            local_anchor_a=(0, 0),
            local_anchor_b=(0, l),
            collide_connected=False,
            enable_motor=True,
            max_motor_torque=100000,
            motor_speed=3,
        )


if __name__ == "__main__":

    ani = b2d.testbed.run(Blender)
    ani