Generate a quasicrystal animation using plato-draw

README.md

apt.txt

povray
xvfb
libglu1-mesa
libgl1-mesa-dri

environment.yml

# specify dependencies for myblender.org operation (see also apt.txt
# for the full set)
channels:
    - conda-forge
dependencies:
    - cython
    - fresnel
    - freud
    - hoomd
    - pyglet
    - pip
    - pip:
      - matplotlib
      - pythreejs
      - git+https://github.com/vispy/vispy
      - plato-draw
      - gtar
      - git+https://github.com/klarh/flowws
      - git+https://github.com/klarh/hoomd_flowws

QC animation.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# set to True to use vispy webGL backend (but disable saving video frames)\n",
    "live = False"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import numpy as np\n",
    "if not live:\n",
    "    import vispy.app; vispy.app.use_app('pyglet')\n",
    "import plato, plato.draw.vispy as draw\n",
    "import ipywidgets"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "L = 50\n",
    "w = .25\n",
    "N = int(L/w)\n",
    "\n",
    "xs = np.linspace(-L/2, L/2, N, endpoint=False)\n",
    "thetas = np.linspace(0, 2*np.pi, 7, endpoint=False)\n",
    "\n",
    "starts = np.array([xs, np.zeros_like(xs) + L]).T\n",
    "ends = np.array([xs, np.zeros_like(xs) - L]).T\n",
    "\n",
    "prim_starts = []\n",
    "prim_ends = []\n",
    "for theta in thetas:\n",
    "    rotmat = np.array([[np.cos(theta), -np.sin(theta)], [np.sin(theta), np.cos(theta)]])\n",
    "    prim_starts.append(np.dot(starts, rotmat))\n",
    "    prim_ends.append(np.dot(ends, rotmat))\n",
    "    \n",
    "def get_colors(t=0):\n",
    "    result = np.ones((len(thetas), N, 4))\n",
    "    lengthscale = 6 + .5*np.sin(t/6 + 3)\n",
    "    for (target, theta) in zip(result, thetas):\n",
    "        target[:, :3] = plato.cmap.cubeellipse(theta, h=1.8)\n",
    "        target[:, :3] *= .5 + .5*np.cos(t + xs*lengthscale)[:, np.newaxis]\n",
    "    result = result.reshape((-1, 4))\n",
    "    return result\n",
    "\n",
    "prim_starts = np.concatenate(prim_starts, axis=0)\n",
    "prim_starts = np.hstack([prim_starts, prim_starts[:, :1]*0])\n",
    "prim_ends = np.concatenate(prim_ends, axis=0)\n",
    "prim_ends = np.hstack([prim_ends, prim_ends[:, :1]*0])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "prim = draw.Lines(\n",
    "    start_points=prim_starts, end_points=prim_ends,\n",
    "    widths=np.ones(len(prim_starts))*w)\n",
    "\n",
    "features = dict(ambient_light=.25, directional_light=[(0, 0, 0)], \n",
    "                additive_rendering=True)\n",
    "scene = draw.Scene(prim, features=features, zoom=60/L)\n",
    "\n",
    "def update(t=0):\n",
    "    prim.colors = get_colors(t)\n",
    "    \n",
    "    theta = 2*np.pi/80*np.cos(t/9)\n",
    "    quat = (np.cos(theta/2), 0, 0, np.sin(theta/2))\n",
    "    scene.rotation = quat\n",
    "    \n",
    "    scene.render()\n",
    "\n",
    "tmax = 48*np.pi\n",
    "\n",
    "if live:\n",
    "    update()\n",
    "    scene.show()\n",
    "    ipywidgets.interact(update, t=(0., tmax))\n",
    "else:\n",
    "    for (i, t) in enumerate(np.linspace(0, tmax, 60*30)):\n",
    "        fname = 'frame.{:05d}.png'.format(i)\n",
    "        update(t)\n",
    "        scene.save(fname)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "!ffmpeg -y -framerate 30 -i frame.%05d.png -filter:v \"crop=(trunc(iw/16)*16):(trunc(ih/16)*16)\" -c:v libx264 -preset slow -crf 20 -threads 4 -pix_fmt yuv420p 7fold.mp4"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "!rm frame.*.png"
   ]
  }
 ],
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start

#!/bin/bash

xvfb-run -a -s "-screen 0 1600x1200x24 +extension GLX +render +iglx" "${@}"