animation of spring-mass-damper system with realistic physics

smd.py

import pygame
import pymunk
import pymunk.pygame_util
import numpy as np
from scipy.signal import sawtooth

# Initialisierung
pygame.init()
WIDTH, HEIGHT = 800, 600
window = pygame.display.set_mode((WIDTH, HEIGHT))
clock = pygame.time.Clock()

# Physik-Space konfigurieren
space = pymunk.Space()
space.gravity = (0, 900)  # Schwerkraft
draw_options = pymunk.pygame_util.DrawOptions(window)

# Boden erstellen
ground = pymunk.Segment(space.static_body, (0, 550), (WIDTH, 550), 5)
ground.friction = 1.0
space.add(ground)

# Anregungsparameter
PERIODE = 3.0  # 3 Sekunden Periodendauer
AMPLITUDE = 100  # Vertikale Amplitude in Pixel

# Feder-Ankerpunkt (kinematischer Körper für Bewegung)
anchor = pymunk.Body(body_type=pymunk.Body.KINEMATIC)
anchor.position = (400, 300)
space.add(anchor)

# Masse erstellen
mass = pymunk.Body()
mass.position = (400, 400)
shape = pymunk.Poly.create_box(mass, (30, 30))
shape.mass = 8.0
shape.friction = 0.5
space.add(mass, shape)

# Feder-Dämpfer-System
spring = pymunk.DampedSpring(
    anchor,
    mass,
    (0, 0),
    (0, 0),
    rest_length=100,
    stiffness=120,  # Federkonstante
    damping=15,  # Dämpfungskoeffizient
)
space.add(spring)


# Dreieckfunktion für vertikale Anregung
def triangle_wave(t):
    phase = sawtooth(2 * np.pi * t / PERIODE, width=0.5)
    return AMPLITUDE * phase


# Hauptsimulationsschleife
running = True
start_time = pygame.time.get_ticks()
while running:
    # Zeitberechnung
    current_time = (pygame.time.get_ticks() - start_time) / 1000.0

    # Ankerposition aktualisieren
    anchor.position = (400, 300 + triangle_wave(current_time))

    # Events verarbeiten
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # Physik-Update
    space.step(1 / 60)

    # Zeichnen
    window.fill((30, 30, 30))
    space.debug_draw(draw_options)
    pygame.draw.line(window, (255, 255, 255), anchor.position, mass.position, 3)

    pygame.display.flip()
    clock.tick(60)

pygame.quit()