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);
}