# Point

VTKExamples/CSharp/GeometricObjects/Point

### Description

A tutorial on how to setup a Windows Forms Application utilizing ActiViz.NET can be found here: Setup a Windows Forms Application to use ActiViz.NET

### Code

Point.cs

    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Windows.Forms;
    using System.Diagnostics;

    using Kitware.VTK;

    namespace ActiViz.Examples {
       public partial class Form1 : Form {
          public Form1() {
             InitializeComponent();
          }

          private void renderWindowControl1_Load(object sender, EventArgs e) {
             try {
                Point();
             }
             catch(Exception ex) {
                MessageBox.Show(ex.Message, "Exception", MessageBoxButtons.OK);
             }
          }

          private void Point() {
             // Create the geometry of the points (the coordinate)
             vtkPoints points = vtkPoints.New();
             double[,] p = new double[,] {
                {1.0, 2.0, 3.0},
                {3.0, 1.0, 2.0},
                {2.0, 3.0, 1.0}
             };

             // Create topology of the points (a vertex per point)
             vtkCellArray vertices = vtkCellArray.New();
             int nPts = 3;

             int[] ids = new int[nPts];
             for(int i = 0; i < nPts; i++)
                ids[i] = points.InsertNextPoint(p[i, 0], p[i, 1], p[i, 2]);

             int size = Marshal.SizeOf(typeof(int)) * nPts;
             IntPtr pIds = Marshal.AllocHGlobal(size);
             Marshal.Copy(ids, 0, pIds, nPts);
             vertices.InsertNextCell(nPts, pIds);
             Marshal.FreeHGlobal(pIds);

             // Create a polydata object
             vtkPolyData pointPoly = vtkPolyData.New();

             // Set the points and vertices we created as the geometry and topology of the polydata
             pointPoly.SetPoints(points);
             pointPoly.SetVerts(vertices);

             // Visualize
             vtkPolyDataMapper mapper = vtkPolyDataMapper.New();
             mapper.SetInput(pointPoly);

             vtkActor actor = vtkActor.New();
             actor.SetMapper(mapper);
             actor.GetProperty().SetPointSize(20);
             vtkRenderWindow renderWindow = renderWindowControl1.RenderWindow;
             vtkRenderer renderer = renderWindow.GetRenderers().GetFirstRenderer();
             renderer.SetBackground(0.3, 0.2, 0.1);
             renderer.AddActor(actor);
          }
       }
    }