examples/04-lights/shadows.ipynb

{
  "cells": [
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "%matplotlib inline\nfrom pyvista import set_plot_theme\nset_plot_theme('document')"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Shadows {#light_shadows_example}\n=======\n\nDemonstrate the usage of lights and shadows in PyVista.\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "import numpy as np\n\nimport pyvista\nfrom pyvista import examples\n\nmesh = examples.download_dragon()\nmesh.rotate_x(90, inplace=True)\nmesh.rotate_z(120, inplace=True)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Using two lights, plot the Stanford Dragon with shadows.\n\n::: {.note}\n::: {.admonition-title}\nNote\n:::\n\nVTK has known issues when rendering shadows on certain window sizes. Be\nprepared to experiment with the `window_size` parameter. An initial\nwindow size of `(1000, 1000)` seems to work well, which can be manually\nresized without issue.\n:::\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "light1 = pyvista.Light(\n    position=(0, 0.2, 1.0),\n    focal_point=(0, 0, 0),\n    color=[1.0, 1.0, 0.9843, 1.0],  # Color temp. 5400 K\n    intensity=0.3,\n)\n\nlight2 = pyvista.Light(\n    position=(0, 1.0, 1.0),\n    focal_point=(0, 0, 0),\n    color=[1.0, 0.83921, 0.6666, 1.0],  # Color temp. 2850 K\n    intensity=1,\n)\n\n# Add a thin box below the mesh\nbounds = mesh.bounds\nrnge = (bounds[1] - bounds[0], bounds[3] - bounds[2], bounds[5] - bounds[4])\n\nexpand = 1.0\nheight = rnge[2] * 0.05\ncenter = np.array(mesh.center)\ncenter -= [0, 0, mesh.center[2] - bounds[4] + height / 2]\n\nwidth = rnge[0] * (1 + expand)\nlength = rnge[1] * (1 + expand)\nbase_mesh = pyvista.Cube(center, width, length, height)\n\n# rotate base and mesh to get a better view\nbase_mesh.rotate_z(30, inplace=True)\nmesh.rotate_z(30, inplace=True)\n\n# create the plotter with custom lighting\npl = pyvista.Plotter(lighting=None, window_size=(800, 800))\npl.add_light(light1)\npl.add_light(light2)\npl.add_mesh(\n    mesh,\n    ambient=0.2,\n    diffuse=0.5,\n    specular=0.5,\n    specular_power=90,\n    smooth_shading=True,\n    color='orange',\n)\npl.add_mesh(base_mesh)\npl.enable_shadows()\npl.camera.zoom(1.5)\npl.show()"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Show light penetrating several planes. Adjust the light intensity and\nthe `shadow_attenuation` to change how many planes the light can go\nthrough.\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "plotter = pyvista.Plotter(lighting=None, window_size=(800, 800))\n\n# add several planes\nfor plane_y in [2, 5, 10]:\n    screen = pyvista.Plane(center=(0, plane_y, 0), direction=(0, 1, 0), i_size=5, j_size=5)\n    plotter.add_mesh(screen, color='white')\n\nlight = pyvista.Light(\n    position=(0, 0, 0),\n    focal_point=(0, 1, 0),\n    color='cyan',\n    intensity=15,\n    positional=True,\n    cone_angle=15,\n    attenuation_values=(2, 0, 0),\n)\nlight.show_actor()\n\nplotter.add_light(light)\nplotter.view_vector((1, -2, 2))\nplotter.enable_shadows()\nplotter.show()"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Here, we use a lower shadow\\_attenuation value to demonstrate how the\nlight can travel through more planes.\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "plotter = pyvista.Plotter(lighting=None, window_size=(800, 800))\n\n# add several planes\nfor plane_y in [2, 5, 10]:\n    screen = pyvista.Plane(center=(0, plane_y, 0), direction=(0, 1, 0), i_size=5, j_size=5)\n    plotter.add_mesh(screen, color='white')\n\nlight = pyvista.Light(\n    position=(0, 0, 0),\n    focal_point=(0, 1, 0),\n    color='cyan',\n    intensity=15,\n    cone_angle=15,\n    shadow_attenuation=0.95,\n    positional=True,\n    attenuation_values=(2, 0, 0),\n)\nlight.show_actor()\n\nplotter.add_light(light)\nplotter.view_vector((1, -2, 2))\nplotter.enable_shadows()\nplotter.show()"
      ]
    }
  ],
  "metadata": {
    "kernelspec": {
      "display_name": "Python 3",
      "language": "python",
      "name": "python3"
    },
    "language_info": {
      "codemirror_mode": {
        "name": "ipython",
        "version": 3
      },
      "file_extension": ".py",
      "mimetype": "text/x-python",
      "name": "python",
      "nbconvert_exporter": "python",
      "pygments_lexer": "ipython3",
      "version": "3.9.16"
    }
  },
  "nbformat": 4,
  "nbformat_minor": 0
}