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CombinePolyData

vtk-examples/Cxx/Filtering/CombinePolyData


Description

This example reads two .vtp files (or produces them if not specified as command line arguments), combines them, and displays the result to the screen.

Other languages

See (Python)

Question

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

Code

CombinePolyData.cxx

#include <vtkActor.h>
#include <vtkAppendPolyData.h>
#include <vtkCamera.h>
#include <vtkCleanPolyData.h>
#include <vtkConeSource.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>
#include <vtkXMLPolyDataReader.h>

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

  vtkNew<vtkPolyData> input1;
  vtkNew<vtkPolyData> input2;

  if (argc == 1) // command line arguments not specified
  {
    vtkNew<vtkSphereSource> sphereSource;
    sphereSource->SetCenter(5, 0, 0);
    sphereSource->Update();

    input1->ShallowCopy(sphereSource->GetOutput());

    vtkNew<vtkConeSource> coneSource;
    coneSource->Update();

    input2->ShallowCopy(coneSource->GetOutput());
  }
  else
  {
    if (argc != 3)
    {
      std::cout << "argc = " << argc << std::endl;
      std::cout << "Required arguments: File1 File2" << std::endl;
      return EXIT_FAILURE;
    }
    std::string inputFilename1 = argv[1];
    std::string inputFilename2 = argv[2];
    vtkNew<vtkXMLPolyDataReader> reader1;
    reader1->SetFileName(inputFilename1.c_str());
    reader1->Update();
    input1->ShallowCopy(reader1->GetOutput());

    vtkNew<vtkXMLPolyDataReader> reader2;
    reader2->SetFileName(inputFilename2.c_str());
    reader2->Update();
    input2->ShallowCopy(reader2->GetOutput());
  }

  // Append the two meshes
  vtkNew<vtkAppendPolyData> appendFilter;
  appendFilter->AddInputData(input1);
  appendFilter->AddInputData(input2);

  // Remove any duplicate points.
  vtkNew<vtkCleanPolyData> cleanFilter;
  cleanFilter->SetInputConnection(appendFilter->GetOutputPort());
  cleanFilter->Update();

  // Create a mapper and actor
  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputConnection(cleanFilter->GetOutputPort());

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);

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

  // Add the actors to the scene
  renderer->AddActor(actor);

  // Render and interact
  renderWindowInteractor->Initialize();
  renderWindow->Render();
  renderer->SetBackground(colors->GetColor3d("deep_ochre").GetData());
  renderer->GetActiveCamera()->Zoom(0.9);
  renderWindow->SetWindowName("CombinePolyData");
  renderWindow->Render();
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(CombinePolyData)

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

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

Download and Build CombinePolyData

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

cd CombinePolyData/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:

./CombinePolyData

WINDOWS USERS

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