# ColoredElevationMap

VTKExamples/CSharp/Meshes/ColoredElevationMap

### 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
Note: As long as ActiViz.NET is not build with VTK version 6.0 or higher you must define the preprocessor directive VTK_MAJOR_VERSION_5.

### Code

ColoredElevationMap.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 {
                ColoredElevationMap();
             }
             catch(Exception ex) {
                MessageBox.Show(ex.Message, "Exception", MessageBoxButtons.OK);
             }
          }

          private void ColoredElevationMap() {
             // Create a grid of points (height/terrian map)
             vtkPoints points = vtkPoints.New();

             uint GridSize = 20;
             double xx, yy, zz;
             for(uint x = 0; x < GridSize; x++) {
                for(uint y = 0; y < GridSize; y++) {
                   xx = x + vtkMath.Random(-.2, .2);
                   yy = y + vtkMath.Random(-.2, .2);
                   zz = vtkMath.Random(-.5, .5);
                   points.InsertNextPoint(xx, yy, zz);
                }
             }

             // Add the grid points to a polydata object
             vtkPolyData inputPolyData = vtkPolyData.New();
             inputPolyData.SetPoints(points);

             // Triangulate the grid points
             vtkDelaunay2D delaunay = vtkDelaunay2D.New();
    #if VTK_MAJOR_VERSION_5
             delaunay.SetInput(inputPolyData);
    #else
             delaunay.SetInputData(inputPolyData);
    #endif
             delaunay.Update();
             vtkPolyData outputPolyData = delaunay.GetOutput();

             double[] bounds = outputPolyData.GetBounds();

             // Find min and max z
             double minz = bounds[4];
             double maxz = bounds[5];

             Debug.WriteLine("minz: " + minz);
             Debug.WriteLine("maxz: " + maxz);

             // Create the color map
             vtkLookupTable colorLookupTable = vtkLookupTable.New();
             colorLookupTable.SetTableRange(minz, maxz);
             colorLookupTable.Build();

             // Generate the colors for each point based on the color map
             vtkUnsignedCharArray colors = vtkUnsignedCharArray.New();
             colors.SetNumberOfComponents(3);
             colors.SetName("Colors");

             Debug.WriteLine("There are " + outputPolyData.GetNumberOfPoints()
                       + " points.");

    #if UNSAFE // fastest way to fill color array
             colors.SetNumberOfTuples(outputPolyData.GetNumberOfPoints());
             unsafe {
                byte* pColor = (byte*)colors.GetPointer(0).ToPointer();

                for(int i = 0; i < outputPolyData.GetNumberOfPoints(); i++) {
                   double[] p = outputPolyData.GetPoint(i);

                   double[] dcolor = colorLookupTable.GetColor(p[2]);
                   Debug.WriteLine("dcolor: "
                             + dcolor[0] + " "
                             + dcolor[1] + " "
                             + dcolor[2]);

                   byte[] color = new byte[3];
                   for(uint j = 0; j < 3; j++) {
                      color[j] = (byte)( 255 * dcolor[j] );
                   }
                   Debug.WriteLine("color: "
                             + color[0] + " "
                             + color[1] + " "
                             + color[2]);

                   *( pColor + 3 * i ) = color[0];
                   *( pColor + 3 * i + 1 ) = color[1];
                   *( pColor + 3 * i + 2 ) = color[2];
                }
             }
    #else
             for(int i = 0; i < outputPolyData.GetNumberOfPoints(); i++) {
                double[] p = outputPolyData.GetPoint(i);

                double[] dcolor = colorLookupTable.GetColor(p[2]);
                Debug.WriteLine("dcolor: "
                          + dcolor[0] + " "
                          + dcolor[1] + " "
                          + dcolor[2]);

                byte[] color = new byte[3];
                for(uint j = 0; j < 3; j++) {
                   color[j] = (byte)( 255 * dcolor[j] );
                }
                Debug.WriteLine("color: "
                          + color[0] + " "
                          + color[1] + " "
                          + color[2]);
                colors.InsertNextTuple3(color[0], color[1], color[2] );
                //IntPtr pColor = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(byte)) * 3);
                //Marshal.Copy(color, 0, pColor, 3);
                //colors.InsertNextTupleValue(pColor);
                //Marshal.FreeHGlobal(pColor);
             }
    #endif

             outputPolyData.GetPointData().SetScalars(colors);

             // Create a mapper and actor
             vtkPolyDataMapper mapper = vtkPolyDataMapper.New();
    #if VTK_MAJOR_VERSION_5
             mapper.SetInputConnection(outputPolyData.GetProducerPort());
    #else
             mapper.SetInputData(outputPolyData);
    #endif

             vtkActor actor = vtkActor.New();
             actor.SetMapper(mapper);

             // get a reference to the renderwindow of our renderWindowControl1
             vtkRenderWindow renderWindow = renderWindowControl1.RenderWindow;
             // renderer
             vtkRenderer renderer = renderWindow.GetRenderers().GetFirstRenderer();
             // set background color
             renderer.SetBackground(0.2, 0.3, 0.4);
             // add our actor to the renderer
             renderer.AddActor(actor);
          }
       }
    }