ColoredElevationMap
VTKExamples/Cxx/Meshes/ColoredElevationMap
Code
ColoredElevationMap.cxx
#include <vtkVersion.h>
#include <vtkSmartPointer.h>
#include <vtkActor.h>
#include <vtkDelaunay2D.h>
#include <vtkLookupTable.h>
#include <vtkMath.h>
#include <vtkPointData.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkVertexGlyphFilter.h>
#include <vtkXMLPolyDataWriter.h>
// For compatibility with new VTK generic data arrays
#ifdef vtkGenericDataArray_h
#define InsertNextTupleValue InsertNextTypedTuple
#endif
int main(int, char *[])
{
// Create a grid of points (height/terrian map)
vtkSmartPointer<vtkPoints> points =
vtkSmartPointer<vtkPoints>::New();
unsigned int GridSize = 20;
double xx, yy, zz;
for(unsigned int x = 0; x < GridSize; x++)
{
for(unsigned int 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
vtkSmartPointer<vtkPolyData> inputPolyData =
vtkSmartPointer<vtkPolyData>::New();
inputPolyData->SetPoints(points);
// Triangulate the grid points
vtkSmartPointer<vtkDelaunay2D> delaunay =
vtkSmartPointer<vtkDelaunay2D>::New();
#if VTK_MAJOR_VERSION <= 5
delaunay->SetInput(inputPolyData);
#else
delaunay->SetInputData(inputPolyData);
#endif
delaunay->Update();
vtkPolyData* outputPolyData = delaunay->GetOutput();
double bounds[6];
outputPolyData->GetBounds(bounds);
// Find min and max z
double minz = bounds[4];
double maxz = bounds[5];
std::cout << "minz: " << minz << std::endl;
std::cout << "maxz: " << maxz << std::endl;
// Create the color map
vtkSmartPointer<vtkLookupTable> colorLookupTable =
vtkSmartPointer<vtkLookupTable>::New();
colorLookupTable->SetTableRange(minz, maxz);
colorLookupTable->Build();
// Generate the colors for each point based on the color map
vtkSmartPointer<vtkUnsignedCharArray> colors =
vtkSmartPointer<vtkUnsignedCharArray>::New();
colors->SetNumberOfComponents(3);
colors->SetName("Colors");
std::cout << "There are " << outputPolyData->GetNumberOfPoints()
<< " points." << std::endl;
for(int i = 0; i < outputPolyData->GetNumberOfPoints(); i++)
{
double p[3];
outputPolyData->GetPoint(i,p);
double dcolor[3];
colorLookupTable->GetColor(p[2], dcolor);
std::cout << "dcolor: "
<< dcolor[0] << " "
<< dcolor[1] << " "
<< dcolor[2] << std::endl;
unsigned char color[3];
for(unsigned int j = 0; j < 3; j++)
{
color[j] = static_cast<unsigned char>(255.0 * dcolor[j]);
}
std::cout << "color: "
<< (int)color[0] << " "
<< (int)color[1] << " "
<< (int)color[2] << std::endl;
colors->InsertNextTupleValue(color);
}
outputPolyData->GetPointData()->SetScalars(colors);
// Create a mapper and actor
vtkSmartPointer<vtkPolyDataMapper> mapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
#if VTK_MAJOR_VERSION <= 5
mapper->SetInputConnection(outputPolyData->GetProducerPort());
#else
mapper->SetInputData(outputPolyData);
#endif
vtkSmartPointer<vtkActor> actor =
vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
// Create a renderer, render window, and interactor
vtkSmartPointer<vtkRenderer> renderer =
vtkSmartPointer<vtkRenderer>::New();
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->AddRenderer(renderer);
vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
renderWindowInteractor->SetRenderWindow(renderWindow);
// Add the actor to the scene
renderer->AddActor(actor);
renderer->SetBackground(.1, .2, .3);
// Render and interact
renderWindow->Render();
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(ColoredElevationMap)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(ColoredElevationMap MACOSX_BUNDLE ColoredElevationMap.cxx)
target_link_libraries(ColoredElevationMap ${VTK_LIBRARIES})
Download and Build ColoredElevationMap
Click here to download ColoredElevationMap and its CMakeLists.txt file. Once the tarball ColoredElevationMap.tar has been downloaded and extracted,
cd ColoredElevationMap/build
If VTK is installed:
cmake ..
If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:
cmake -DVTK_DIR:PATH=/home/me/vtk_build ..
Build the project:
make
and run it:
./ColoredElevationMap
WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.