.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "auto_examples/04_demos/collision-particles.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note Click :ref:`here ` to download the full example code .. rst-class:: sphx-glr-example-title .. _sphx_glr_auto_examples_04_demos_collision-particles.py: Collisions of particles in a box ================================ This is a simple demonstration of how you can simulate moving particles in a box using FURY. .. GENERATED FROM PYTHON SOURCE LINES 10-15 In this example, the particles collide with each other and with the walls of the container. When the collision happens between two particles, the particle with less velocity changes its color and gets the same color as the particle with higher velocity. For simplicity, in this demo we do not apply forces. .. GENERATED FROM PYTHON SOURCE LINES 15-22 .. code-block:: default import itertools import numpy as np from fury import actor, ui, utils, window .. GENERATED FROM PYTHON SOURCE LINES 23-24 Here, we define the edges of the box. .. GENERATED FROM PYTHON SOURCE LINES 24-45 .. code-block:: default def box_edges(box_lx, box_ly, box_lz): edge1 = 0.5 * np.array( [ [box_lx, box_ly, box_lz], [box_lx, box_ly, -box_lz], [-box_lx, box_ly, -box_lz], [-box_lx, box_ly, box_lz], [box_lx, box_ly, box_lz], ] ) edge2 = 0.5 * np.array([[box_lx, box_ly, box_lz], [box_lx, -box_ly, box_lz]]) edge3 = 0.5 * np.array([[box_lx, box_ly, -box_lz], [box_lx, -box_ly, -box_lz]]) edge4 = 0.5 * np.array([[-box_lx, box_ly, -box_lz], [-box_lx, -box_ly, -box_lz]]) edge5 = 0.5 * np.array([[-box_lx, box_ly, box_lz], [-box_lx, -box_ly, box_lz]]) lines = [edge1, -edge1, edge2, edge3, edge4, edge5] return lines .. GENERATED FROM PYTHON SOURCE LINES 46-49 Here we define collision between walls-particles and particle-particle. When collision happens, the particle with lower velocity gets the color of the particle with higher velocity .. GENERATED FROM PYTHON SOURCE LINES 49-101 .. code-block:: default def collision(): global xyz num_vertices = vertices.shape[0] sec = int(num_vertices / num_particles) for i, j in np.ndindex(num_particles, num_particles): if i == j: continue distance = np.linalg.norm(xyz[i] - xyz[j]) vel_mag_i = np.linalg.norm(vel[i]) vel_mag_j = np.linalg.norm(vel[j]) # Collision happens if the distance between the centers of two # particles is less or equal to the sum of their radii if distance <= (radii[i] + radii[j]): vel[i] = -vel[i] vel[j] = -vel[j] if vel_mag_j > vel_mag_i: vcolors[i * sec : i * sec + sec] = vcolors[j * sec : j * sec + sec] if vel_mag_i > vel_mag_j: vcolors[j * sec : j * sec + sec] = vcolors[i * sec : i * sec + sec] xyz[i] = xyz[i] + vel[i] * dt xyz[j] = xyz[j] + vel[j] * dt # Collision between particles-walls; vel[:, 0] = np.where( ( (xyz[:, 0] <= -0.5 * box_lx + radii[:]) | (xyz[:, 0] >= (0.5 * box_lx - radii[:])) ), -vel[:, 0], vel[:, 0], ) vel[:, 1] = np.where( ( (xyz[:, 1] <= -0.5 * box_ly + radii[:]) | (xyz[:, 1] >= (0.5 * box_ly - radii[:])) ), -vel[:, 1], vel[:, 1], ) vel[:, 2] = np.where( ( (xyz[:, 2] <= -0.5 * box_lz + radii[:]) | (xyz[:, 2] >= (0.5 * box_lz - radii[:])) ), -vel[:, 2], vel[:, 2], ) .. GENERATED FROM PYTHON SOURCE LINES 102-104 We define position, velocity, color and radius randomly for 50 particles inside the box. .. GENERATED FROM PYTHON SOURCE LINES 104-119 .. code-block:: default global xyz num_particles = 50 box_lx = 20 box_ly = 20 box_lz = 10 steps = 1000 dt = 0.05 xyz = ( np.array([box_lx, box_ly, box_lz]) * (np.random.rand(num_particles, 3) - 0.5) * 0.6 ) vel = 4 * (np.random.rand(num_particles, 3) - 0.5) colors = np.random.rand(num_particles, 3) radii = np.random.rand(num_particles) + 0.01 .. GENERATED FROM PYTHON SOURCE LINES 120-122 With box, streamtube and sphere actors, we can create the box, the edges of the box and the spheres respectively. .. GENERATED FROM PYTHON SOURCE LINES 122-181 .. code-block:: default scene = window.Scene() box_centers = np.array([[0, 0, 0]]) box_directions = np.array([[0, 1, 0]]) box_colors = np.array([[1, 1, 1, 0.2]]) box_actor = actor.box( box_centers, box_directions, box_colors, scales=(box_lx, box_ly, box_lz) ) scene.add(box_actor) lines = box_edges(box_lx, box_ly, box_lz) line_actor = actor.streamtube(lines, colors=(1, 0.5, 0), linewidth=0.1) scene.add(line_actor) sphere_actor = actor.sphere(centers=xyz, colors=colors, radii=radii) scene.add(sphere_actor) showm = window.ShowManager( scene, size=(900, 768), reset_camera=True, order_transparent=True ) tb = ui.TextBlock2D(bold=True) scene.zoom(0.8) scene.azimuth(30) # use itertools to avoid global variables counter = itertools.count() vertices = utils.vertices_from_actor(sphere_actor) vcolors = utils.colors_from_actor(sphere_actor, 'colors') no_vertices_per_sphere = len(vertices) / num_particles initial_vertices = vertices.copy() - np.repeat(xyz, no_vertices_per_sphere, axis=0) def timer_callback(_obj, _event): global xyz cnt = next(counter) tb.message = "Let's count up to 1000 and exit :" + str(cnt) xyz = xyz + vel * dt collision() vertices[:] = initial_vertices + np.repeat(xyz, no_vertices_per_sphere, axis=0) utils.update_actor(sphere_actor) scene.reset_clipping_range() showm.render() if cnt == steps: showm.exit() scene.add(tb) showm.add_timer_callback(True, 50, timer_callback) interactive = False if interactive: showm.start() window.record(showm.scene, size=(900, 768), out_path='simple_collisions.png') .. image-sg:: /auto_examples/04_demos/images/sphx_glr_collision-particles_001.png :alt: collision particles :srcset: /auto_examples/04_demos/images/sphx_glr_collision-particles_001.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-timing **Total running time of the script:** ( 0 minutes 0.128 seconds) .. _sphx_glr_download_auto_examples_04_demos_collision-particles.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: collision-particles.py ` .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: collision-particles.ipynb ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_