{
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "# Create VTK Objects\n\nThis exercise walks through the creation of a few different types of VTK\ndatasets.\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "import numpy as np\nimport pyvista as pv\nimport vtk\n\ntry:\n    from vtkmodules.util.numpy_support import numpy_to_vtk\nexcept:  # noqa: E722\n    from vtk.util.numpy_support import numpy_to_vtk"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "# Create `vtkImageData`\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "image = vtk.vtkImageData()\nimage.SetDimensions(10, 10, 2)\nimage.SetSpacing(1, 2, 5)\nimage.SetOrigin(-0.5, -3, 0)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Add point data\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "values = np.arange(np.prod(image.GetDimensions()))\n# Convert numpy array to VTK array\narr = numpy_to_vtk(values)\narr.SetName(\"values\")  # CRITICAL\nimage.GetPointData().SetScalars(arr)\nimage"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Plot with PyVista for simplicity\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "pv.plot(image, show_edges=True)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "# Create `vtkStructuredGrid`\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "# Define structured points with NumPy\nx = np.arange(-10, 10, 0.25)\ny = np.arange(-10, 10, 0.25)\nx, y = np.meshgrid(x, y)\nr = np.sqrt(x**2 + y**2)\nz = np.sin(r)\n\n# Join the points\nvalues = np.c_[x.ravel(), y.ravel(), z.ravel()]\n\ncoords = numpy_to_vtk(values)\n\npoints = vtk.vtkPoints()\npoints.SetData(coords)\n\ngrid = vtk.vtkStructuredGrid()\ngrid.SetDimensions(*z.shape, 1)\ngrid.SetPoints(points)\ngrid"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Add point data\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "arr = numpy_to_vtk(z.ravel())\narr.SetName(\"z\")  # CRITICAL\ngrid.GetPointData().SetScalars(arr)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Plot with PyVista for simplicity\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "pv.plot(grid, show_edges=True)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "```{=html}\n<center>\n  <a target=\"_blank\" href=\"https://colab.research.google.com/github/pyvista/pyvista-tutorial/blob/gh-pages/notebooks/tutorial/06_vtk/b_create_vtk.ipynb\">\n    <img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/ width=\"150px\">\n  </a>\n</center>\n```\n"
      ]
    }
  ],
  "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": "3.12.11"
    }
  },
  "nbformat": 4,
  "nbformat_minor": 0
}