Hawaii
Repository source: 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.
Info
See Figure 6-12 in Chapter 6 the VTK Textbook.
Other languages
See (Python)
Question
If you have a question about this example, please use the VTK Discourse Forum
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.