# TransformPolyData

VTKExamples/Cxx/Filtering/TransformPolyData

### Description

This example demonstrates how to apply a transform to a data set. It uses vtkTransformPolyDataFilter, but it can be replaced with vtkTransformFilter for different types of data sets, including vtkUnstructuredGrid and vtkStructuredGrid. vtkTransformFilter will work with vtkPolyData, too).

### Code

TransformPolyData.cxx

    #include <vtkSmartPointer.h>
    #include <vtkSphereSource.h>
    #include <vtkPolyData.h>
    #include <vtkTransform.h>
    #include <vtkTransformPolyDataFilter.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>

    int main(int, char *[])
    {
      // Create the polydata geometry

      vtkSmartPointer<vtkSphereSource> sphereSource =
        vtkSmartPointer<vtkSphereSource>::New();
      sphereSource->Update();

      // Set up the actor to display the untransformed polydata

      vtkSmartPointer<vtkPolyDataMapper> originalMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      originalMapper->SetInputConnection(sphereSource->GetOutputPort());

      vtkSmartPointer<vtkActor> originalActor =
        vtkSmartPointer<vtkActor>::New();
      originalActor->SetMapper(originalMapper);
      originalActor->GetProperty()->SetColor(1,0,0);

      // Set up the transform filter

      vtkSmartPointer<vtkTransform> translation =
        vtkSmartPointer<vtkTransform>::New();
      translation->Translate(1.0, 2.0, 3.0);

      vtkSmartPointer<vtkTransformPolyDataFilter> transformFilter =
        vtkSmartPointer<vtkTransformPolyDataFilter>::New();
      transformFilter->SetInputConnection(sphereSource->GetOutputPort());
      transformFilter->SetTransform(translation);
      transformFilter->Update();

      // Set up the actor to display the transformed polydata

      vtkSmartPointer<vtkPolyDataMapper> transformedMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      transformedMapper->SetInputConnection(transformFilter->GetOutputPort());

      vtkSmartPointer<vtkActor> transformedActor =
        vtkSmartPointer<vtkActor>::New();
      transformedActor->SetMapper(transformedMapper);
      transformedActor->GetProperty()->SetColor(0,1,0);

      // Set up the rest of the visualization pipeline

      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      renderer->AddActor(originalActor);
      renderer->AddActor(transformedActor);
      renderer->SetBackground(.3, .6, .3); // Set renderer's background color to green

      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);

      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(TransformPolyData)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(TransformPolyData MACOSX_BUNDLE TransformPolyData.cxx)

    target_link_libraries(TransformPolyData ${VTK_LIBRARIES})

### Download and Build TransformPolyData

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

    cd TransformPolyData/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:

    ./TransformPolyData

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