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Hawaii

vtk-examples/Cxx/Visualization/Hawaii


Description

Visualize elevations by coloring the scalar values with a lookup table.

This is a translation of the original hawaii.tcl with a few additional enhancements.
The image is centered on Honolulu. Diamond Head is the crater lower left. Punchbowl is the crater in the centre.

Other languages

See (Python)

Question

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Code

Hawaii.cxx

// Translated from hawaii.tcl

/*

Produce figure 6-12 from the VTK Textbook.
It is a translation of the original hawaii.tcl with a few additional
enhancements.
The image is centered on Honolulu, O'ahu.
Diamond Head is the crater lower left. Punchbowl is the crater in the centre.

The colorScheme option allows you to select a series of colour schemes.
0: The default, a lookup using a "Brewer" palette.
1: The original: A lookup table of 256 colours ranging from deep blue (water) to
yellow-white (mountain top).
2: A lookup table with a preset number of colours.

*/

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkColorSeries.h>
#include <vtkDataSetMapper.h>
#include <vtkElevationFilter.h>
#include <vtkLookupTable.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyData.h>
#include <vtkPolyDataReader.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

#include <array>
#include <iostream>
#include <string>

namespace {
//! Create a lookup table.
/*!
@param lut - An indexed lookup table.
*/
void MakeLUT(int const& colorScheme, vtkLookupTable* lut);
} // namespace

int main(int argc, char* argv[])
{

  if (argc < 2)
  {
    std::cout << "Usage: " << argv[0] << " filename [colorScheme]" << std::endl;
    std::cout << "where: filename is the file honolulu.vtk." << std::endl;
    std::cout << "       colorScheme is 0, 1, or 2, default 0" << std::endl;
    return EXIT_FAILURE;
  }

  int colorScheme = 0;
  std::string fileName = argv[1];

  if (argc == 3)
  {
    colorScheme = std::abs(atoi(argv[2]));
    colorScheme = (colorScheme > 2) ? 0 : colorScheme;
  }

  vtkNew<vtkNamedColors> colors;

  // Set the background color.
  std::array<unsigned char, 4> bkg{{26, 51, 102, 255}};
  colors->SetColor("BkgColor", bkg.data());

  // Read a vtk file
  //
  vtkNew<vtkPolyDataReader> hawaii;
  hawaii->SetFileName(fileName.c_str());
  hawaii->Update();
  double bounds[6];
  hawaii->GetOutput()->GetBounds(bounds);

  vtkNew<vtkElevationFilter> elevation;
  elevation->SetInputConnection(hawaii->GetOutputPort());
  elevation->SetLowPoint(0, 0, 0);
  elevation->SetHighPoint(0, 0, 1000);
  elevation->SetScalarRange(0, 1000);

  vtkNew<vtkLookupTable> lut;
  MakeLUT(colorScheme, lut);

  vtkNew<vtkDataSetMapper> hawaiiMapper;
  hawaiiMapper->SetInputConnection(elevation->GetOutputPort());
  hawaiiMapper->SetScalarRange(0, 1000);
  hawaiiMapper->ScalarVisibilityOn();
  hawaiiMapper->SetLookupTable(lut);

  vtkNew<vtkActor> hawaiiActor;
  hawaiiActor->SetMapper(hawaiiMapper);

  // Create the RenderWindow, Renderer and both Actors
  //
  vtkNew<vtkRenderer> ren;
  vtkNew<vtkRenderWindow> renWin;
  renWin->AddRenderer(ren);

  vtkNew<vtkRenderWindowInteractor> iren;
  iren->SetRenderWindow(renWin);

  // Add the actors to the renderer, set the background and size
  //
  ren->AddActor(hawaiiActor);
  // Match the window shape to the object.
  // renWin->SetSize(500, int(500 * bounds[1] / bounds[3]));
  renWin->SetSize(500, 500);
  renWin->SetWindowName("Hawaii");

  // Render the image.
  // Centered on Honolulu,
  // Diamond Head is the crater lower left.
  // Punchbowl is the crater in the centre.
  renWin->Render();
  ren->SetBackground(colors->GetColor3d("BkgColor").GetData());
  ren->GetActiveCamera()->Zoom(1.5);
  ren->GetActiveCamera()->Roll(-90);
  ren->ResetCameraClippingRange();

  renWin->Render();
  iren->Start();

  return EXIT_SUCCESS;
}

namespace {
void MakeLUT(int const& colorScheme, vtkLookupTable* lut)
{
  vtkNew<vtkNamedColors> colors;
  // Select a color scheme.
  switch (colorScheme)
  {
  case 0:
  default: {
    // Make the lookup using a Brewer palette.
    vtkNew<vtkColorSeries> colorSeries;
    colorSeries->SetNumberOfColors(8);
    int colorSeriesEnum = colorSeries->BREWER_DIVERGING_BROWN_BLUE_GREEN_8;
    colorSeries->SetColorScheme(colorSeriesEnum);
    colorSeries->BuildLookupTable(lut, colorSeries->ORDINAL);
    lut->SetNanColor(1, 0, 0, 1);
    break;
  }
  case 1: {
    // A lookup table of 256 colours ranging from
    //  deep blue(water) to yellow - white(mountain top)
    //  is used to color map this figure.
    lut->SetHueRange(0.7, 0);
    lut->SetSaturationRange(1.0, 0);
    lut->SetValueRange(0.5, 1.0);
    break;
  }
  case 2:
    // Make the lookup table with a preset number of colours.
    vtkNew<vtkColorSeries> colorSeries;
    colorSeries->SetNumberOfColors(8);
    colorSeries->SetColorSchemeName("Hawaii");
    colorSeries->SetColor(0, colors->GetColor3ub("turquoise_blue"));
    colorSeries->SetColor(1, colors->GetColor3ub("sea_green_medium"));
    colorSeries->SetColor(2, colors->GetColor3ub("sap_green"));
    colorSeries->SetColor(3, colors->GetColor3ub("green_dark"));
    colorSeries->SetColor(4, colors->GetColor3ub("tan"));
    colorSeries->SetColor(5, colors->GetColor3ub("beige"));
    colorSeries->SetColor(6, colors->GetColor3ub("light_beige"));
    colorSeries->SetColor(7, colors->GetColor3ub("bisque"));
    colorSeries->BuildLookupTable(lut, colorSeries->ORDINAL);
    lut->SetNanColor(1, 0, 0, 1);
  };
}
} // namespace

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(Hawaii)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  CommonDataModel
  FiltersCore
  IOLegacy
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "Hawaii: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
add_executable(Hawaii MACOSX_BUNDLE Hawaii.cxx )
  target_link_libraries(Hawaii PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS Hawaii
  MODULES ${VTK_LIBRARIES}
)

Download and Build Hawaii

Click here to download Hawaii and its CMakeLists.txt file. Once the tarball Hawaii.tar has been downloaded and extracted,

cd Hawaii/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:

./Hawaii

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.