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ColorTransferFunction

vtk-examples/Cxx/Utilities/ColorTransferFunction

Description

This example demonstrates how to map the values (0.0 to 10.0) to the colors (red to green).

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

ColorTransferFunction.cxx

#include <vtkColorTransferFunction.h>
#include <vtkNew.h>

int main(int, char*[])
{
  vtkNew<vtkColorTransferFunction> colorTransferFunction;

  colorTransferFunction->AddRGBPoint(0.0, 1, 0, 0);
  colorTransferFunction->AddRGBPoint(10.0, 0, 1, 0);

  double color[3];
  colorTransferFunction->GetColor(1.0, color);
  std::cout << color[0] << " " << color[1] << " " << color[2] << std::endl;

  colorTransferFunction->GetColor(5.0, color);
  std::cout << color[0] << " " << color[1] << " " << color[2] << std::endl;

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(ColorTransferFunction)

find_package(VTK COMPONENTS 
  vtkCommonCore
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping ColorTransferFunction: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(ColorTransferFunction MACOSX_BUNDLE ColorTransferFunction.cxx )
  target_link_libraries(ColorTransferFunction PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(ColorTransferFunction MACOSX_BUNDLE ColorTransferFunction.cxx )
  target_link_libraries(ColorTransferFunction PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS ColorTransferFunction
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build ColorTransferFunction

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

cd ColorTransferFunction/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:

./ColorTransferFunction

WINDOWS USERS

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