scenepic/python_examples/getting_started.ipynb

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    "import numpy as np\r\n",
    "import scenepic as sp\r\n",
    "\r\n",
    "\r\n",
    "# when we build a ScenePic we are essentially building a web\r\n",
    "# page, and the ScenePic will automatically populate parts of\r\n",
    "# that webpage. \r\n",
    "\r\n",
    "# the scene object acts as the root of the entire ScenePic environment\r\n",
    "scene = sp.Scene()\r\n",
    "\r\n",
    "# you can use it to create one or more canvases to display 3D or 2D\r\n",
    "# objects. Canvas objects display Frames. For a static ScenePic, there\r\n",
    "# will only be a single Frame, but you can use multiple frames to create\r\n",
    "# an animation or to display a range of visualizations in the same visual\r\n",
    "# space. We will create one 3D canvas to display the full scene, and then\r\n",
    "# some 2D canvases which will show projections of the scene.\r\n",
    "main = scene.create_canvas_3d(width=600, height=600)\r\n",
    "projx = scene.create_canvas_2d(\"projx\", width=200, height=200)\r\n",
    "projy = scene.create_canvas_2d(\"projy\", width=200, height=200)\r\n",
    "projz = scene.create_canvas_2d(\"projz\", width=200, height=200)\r\n",
    "\r\n",
    "# the scene object is also used to create Mesh objects that will be added\r\n",
    "# to frames. We are going to create an animation of some spheres orbiting\r\n",
    "# a fixed cube, so let's create a default unit cube to start.\r\n",
    "cube = scene.create_mesh(\"cube\")\r\n",
    "\r\n",
    "# the Mesh object has a variety of methods for adding primitive objects\r\n",
    "# or loading arbitrary mesh geometry. In this example, we will just\r\n",
    "# be using primitives, but the python tutorial shows all the various\r\n",
    "# methods for adding geometry to a mesh.\r\n",
    "cube.add_cube(color=sp.Colors.White)\r\n",
    "\r\n",
    "# let's create our spheres as well, using some different colors\r\n",
    "sphere_names = [\"red\", \"green\", \"blue\"]\r\n",
    "sphere_colors = [sp.Colors.Red, sp.Colors.Green, sp.Colors.Blue]\r\n",
    "spheres = []\r\n",
    "for name, color in zip(sphere_names, sphere_colors):\r\n",
    "    # by placing each sphere on a different layer, we can toggle them on and off\r\n",
    "    sphere = scene.create_mesh(\"{}_sphere\".format(name), layer_id=name)\r\n",
    "    sphere.add_sphere(color=color, transform=sp.Transforms.scale(0.5))\r\n",
    "    spheres.append(sphere)\r\n",
    "\r\n",
    "# now we will iteratively create each frame of the animation.\r\n",
    "for i in range(180):\r\n",
    "    # first we create a frame object. This will be used to populate\r\n",
    "    # the 3D canvas.\r\n",
    "    main_frame = main.create_frame()\r\n",
    "\r\n",
    "    # Now that we have a frame, we can add the cube mesh to the frame\r\n",
    "    main_frame.add_mesh(cube)\r\n",
    "\r\n",
    "    # Next, we add the spheres. ScenePic has a variety of useful tools\r\n",
    "    # for operating on 3D data. Some of the most useful enable us to\r\n",
    "    # create transforms to move meshes around. Let's create the\r\n",
    "    # transforms for our three rotating spheres and add them to the frame.\r\n",
    "    # NB The Python interface uses numpy for matrices and vectors.\r\n",
    "    positions = np.concatenate([np.eye(3, dtype=np.float32) * 1.3,\r\n",
    "                                np.ones((3, 1), dtype=np.float32)], axis=-1)\r\n",
    "    inc = 2 * np.pi / 180\r\n",
    "    positions[0] = sp.Transforms.RotationAboutYAxis(inc * i) @ positions[0].T\r\n",
    "    positions[1] = sp.Transforms.RotationAboutZAxis(2 * inc * i) @ positions[1].T\r\n",
    "    positions[2] = sp.Transforms.RotationAboutXAxis(3 * inc * i) @ positions[2].T\r\n",
    "    positions = positions[:, :3]\r\n",
    "    for sphere, position in zip(spheres, positions):\r\n",
    "        transform = sp.Transforms.translate(position)\r\n",
    "        main_frame.add_mesh(sphere, transform=transform)\r\n",
    "\r\n",
    "    # now we'll populate our projections\r\n",
    "    for j, proj in enumerate([projx, projy, projz]):\r\n",
    "        proj_frame = proj.create_frame()\r\n",
    "\r\n",
    "        # 2D frames work in pixels (as oppose to world units) so we need\r\n",
    "        # to convert positions to pixels.\r\n",
    "        proj_frame.add_rectangle(75, 75, 50, 50, fill_color=sp.Colors.White)\r\n",
    "        points = np.roll(positions, j, axis=1)[:, 1:]\r\n",
    "        points[:, 1] *= -1\r\n",
    "        points = points * 50 + 100\r\n",
    "\r\n",
    "        for point, color in zip(points, sphere_colors):\r\n",
    "            proj_frame.add_circle(point[0], point[1], 12.5, fill_color=color)\r\n",
    "\r\n",
    "        proj_frame.add_text(proj.canvas_id, 10, 190, size_in_pixels=16)\r\n",
    "            \r\n",
    "# this will make user interactions happen to all canvases simultaneously\r\n",
    "scene.link_canvas_events(main, projx, projy, projz)\r\n",
    "\r\n",
    "# ScenePic provides some useful layout controls by exposing CSS grid commands\r\n",
    "scene.grid(width=\"800px\", grid_template_rows=\"200px 200px 200px\", grid_template_columns=\"600px 200px\")\r\n",
    "scene.place(main.canvas_id, \"1 / span 3\", \"1\")\r\n",
    "scene.place(projx.canvas_id, \"1\", \"2\")\r\n",
    "scene.place(projy.canvas_id, \"2\", \"2\")\r\n",
    "scene.place(projz.canvas_id, \"3\", \"2\")\r\n",
    "\r\n",
    "# display the scene in Jupyter\r\n",
    "scene\r\n"
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