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ProgrammableFilter

vtk-examples/Cxx/Filtering/ProgrammableFilter


Question

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Code

ProgrammableFilter.cxx

#include <vtkActor.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProgrammableFilter.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>

namespace {

struct params
{
  vtkPolyData* data;
  vtkProgrammableFilter* filter;
};

void AdjustPoints(void* arguments);

} // namespace

int main(int, char*[])
{
  vtkNew<vtkNamedColors> colors;

  // Create a sphere
  vtkNew<vtkSphereSource> sphereSource;
  sphereSource->Update();

  vtkNew<vtkProgrammableFilter> programmableFilter;
  programmableFilter->SetInputConnection(sphereSource->GetOutputPort());

  params myParams;
  myParams.data = sphereSource->GetOutput();
  myParams.filter = programmableFilter;

  programmableFilter->SetExecuteMethod(AdjustPoints, &myParams);
  programmableFilter->Update();

  // Create a mapper and actor
  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputConnection(programmableFilter->GetOutputPort());
  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->GetProperty()->SetColor(
      colors->GetColor3d("LightGoldenrodYellow").GetData());

  // Create a renderer, render window, and interactor
  vtkNew<vtkRenderer> renderer;
  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);

  // Add the actor to the scene
  renderer->AddActor(actor);
  renderer->SetBackground(colors->GetColor3d("SteelBLue").GetData());

  // Render and interact
  renderWindow->SetWindowName("ProgrammableFilter");
  renderWindow->Render();
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

namespace {

void AdjustPoints(void* arguments)
{
  params* input = static_cast<params*>(arguments);

  vtkPoints* inPts = input->data->GetPoints();
  vtkIdType numPts = inPts->GetNumberOfPoints();
  vtkNew<vtkPoints> newPts;
  newPts->SetNumberOfPoints(numPts);

  for (vtkIdType i = 0; i < numPts / 2; i++)
  {
    double p[3];
    inPts->GetPoint(i, p);
    p[0] = p[0] + .5;
    p[1] = p[1] + .5;
    p[2] = p[2] + .5;
    newPts->SetPoint(i, p);
  }

  for (vtkIdType i = numPts / 2; i < numPts; i++)
  {
    double p[3];
    inPts->GetPoint(i, p);
    p[0] = p[0] - .5;
    p[1] = p[1] - .5;
    p[2] = p[2] - .5;
    newPts->SetPoint(i, p);
  }

  input->filter->GetPolyDataOutput()->CopyStructure(input->data);
  input->filter->GetPolyDataOutput()->SetPoints(newPts);
}

} // namespace

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(ProgrammableFilter)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  FiltersProgrammable
  FiltersSources
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "ProgrammableFilter: 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(ProgrammableFilter MACOSX_BUNDLE ProgrammableFilter.cxx )
  target_link_libraries(ProgrammableFilter PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS ProgrammableFilter
  MODULES ${VTK_LIBRARIES}
)

Download and Build ProgrammableFilter

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

cd ProgrammableFilter/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:

./ProgrammableFilter

WINDOWS USERS

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