Manim pymunk integration. Fluid simulation.

gistfile1.py

import pymunk
from manim import *
import random



# transform the pymunk position to manim position
def transform_pymunk_to_manim_position(p):
    return p[0] / 100.0, p[1] / 100.0, 0

class PymunkCircle(Circle):
    def __init__(self, x, y, mass, moment, space, radius, **kwargs):
        self.body = pymunk.Body(mass, moment)
        self.body.position = x, y
        self.shape = pymunk.Circle(self.body, radius)
        self.shape.elasticity = 0.93
        space.add(self.body, self.shape)
        super().__init__(radius=radius / 100.0, **kwargs)

    def update_position(self):
        position = transform_pymunk_to_manim_position(self.body.position)
        self.move_to(position)


class PymunkLine(Line):
    def __init__(self, p1, p2, space, elasticity, stroke_width, **kwargs):
        self.shape = pymunk.Segment(space.static_body, p1, p2, stroke_width)
        self.shape.elasticity = elasticity
        space.add(self.shape)
        super().__init__(start=transform_pymunk_to_manim_position(p1), end=transform_pymunk_to_manim_position(p2), stroke_width=stroke_width, **kwargs)

class TestPymunk(Scene):

    def construct(self):
        def update_circle(mo, dt):
            mo.update_position()
            
        def update_scene(dt):
            self.space.step(1/FPS)

        FPS = 80.0
        self.space = pymunk.Space()
        self.space.gravity = 0, -200

        p1 = (-200, -200)
        p2 = (200, -200)
        p3 = (-200, 200)
        p4 = (200, 200)
        stroke_width = 3
        barier1 = PymunkLine(p1, p2, self.space, 1, stroke_width=stroke_width)
        barier2 = PymunkLine(p1, p3, self.space, 1, stroke_width=stroke_width)
        barier3 = PymunkLine(p2, p4, self.space, 1, stroke_width=stroke_width)

        PymunkCircle.set_default(radius=3, fill_color=BLUE, fill_opacity=0.8, stroke_opacity=1, stroke_width=2, color=BLUE)
        circles_count = 1500
        circles = VGroup(*[PymunkCircle((i % 30) * 10 - 180 + int(i / 30) * 1,
                                        int(i / 30) * 10 - 150,
                                        mass=5, moment=100, space=self.space) for i in range(circles_count)])
        [circles[i].add_updater(update_circle) for i in range(circles_count)]
        self.add_updater(update_scene)
        
        self.wait(0.1)
        self.add(circles, barier1, barier2, barier3)
        self.wait(10)


with tempconfig({"quality": "high_quality", "preview": True}):
    TestPymunk().render()