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    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
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      },
      "outputs": [],
      "source": [
        "%matplotlib inline"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "# Types of Shading {#shading_example}\n\nComparison of default, flat shading vs. smooth shading.\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "import pyvista\nfrom pyvista import examples"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "PyVista supports two types of shading: flat and smooth shading that uses\nVTK\\'s Phong shading algorithm.\n\nThis is a plot with the default flat shading.\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "mesh = examples.load_nut()\nmesh.plot()"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Here\\'s the same sphere with smooth shading.\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "mesh.plot(smooth_shading=True)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Note how smooth shading makes edges that should be sharp look odd, it\\'s\nbecause the points of these normals are averaged between two faces that\nhave a sharp angle between them. You can avoid this by enabling\n`split_sharp_edges`.\n\n::: note\n::: title\nNote\n:::\n\nYou can configure the splitting angle with the optional `feature_angle`\nkeyword argument.\n:::\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "mesh.plot(smooth_shading=True, split_sharp_edges=True)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "We can even plot the edges that will be split using\n`extract_feature_edges <pyvista.DataSetFilters.extract_feature_edges>`{.interpreted-text\nrole=\"func\"}.\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "# extract the feature edges exceeding 30 degrees\nedges = mesh.extract_feature_edges(\n    boundary_edges=False,\n    non_manifold_edges=False,\n    feature_angle=30,\n    manifold_edges=False,\n)\n\n# plot both the edges and the smoothed mesh\npl = pyvista.Plotter()\npl.enable_anti_aliasing()\npl.add_mesh(mesh, smooth_shading=True, split_sharp_edges=True)\npl.add_mesh(edges, color='k', line_width=5)\npl.show()"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "The `split_sharp_edges` keyword argument is compatible with physically\nbased rendering as well.\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "# plot both the edges and the smoothed mesh\n\n\npl = pyvista.Plotter()\npl.enable_anti_aliasing()\npl.add_mesh(mesh, color='w', split_sharp_edges=True, pbr=True, metallic=1.0, roughness=0.5)\npl.show()"
      ]
    }
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