# ImplicitModeller

VTKExamples/Cxx/PolyData/ImplicitModeller

### Code

ImplicitModeller.cxx

    #include <vtkVersion.h>
    #include <vtkSmartPointer.h>
    #include <vtkImplicitModeller.h>
    #include <vtkSphereSource.h>
    #include <vtkPolyData.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkContourFilter.h>
    #include <vtkXMLPolyDataReader.h>

    int main(int argc, char *argv[])
    {
      vtkSmartPointer<vtkPolyData> inputPolyData;
      if(argc > 1)
      {
        vtkSmartPointer<vtkXMLPolyDataReader> reader =
          vtkSmartPointer<vtkXMLPolyDataReader>::New();
        reader->SetFileName(argv[1]);
        reader->Update();
        inputPolyData = reader->GetOutput();
      }
      else
      {
        vtkSmartPointer<vtkSphereSource> sphereSource =
          vtkSmartPointer<vtkSphereSource>::New();
        sphereSource->SetPhiResolution(15);
        sphereSource->SetThetaResolution(15);
        sphereSource->Update();
        inputPolyData = sphereSource->GetOutput();
      }

      vtkSmartPointer<vtkImplicitModeller> implicitModeller =
        vtkSmartPointer<vtkImplicitModeller>::New();
      implicitModeller->SetSampleDimensions(50,50,50);
    #if VTK_MAJOR_VERSION <= 5
      implicitModeller->SetInput(inputPolyData);
    #else
      implicitModeller->SetInputData(inputPolyData);
    #endif
      implicitModeller->AdjustBoundsOn();
      implicitModeller->SetAdjustDistance(.1); // Adjust by 10%
      implicitModeller->SetMaximumDistance(.1);

      // Compute the range to select a reasonable contour value
      double bounds[6];
      inputPolyData->GetBounds(bounds);
      double xrange = bounds[1] - bounds[0];

      // Create the 0 isosurface
      vtkSmartPointer<vtkContourFilter> contourFilter =
        vtkSmartPointer<vtkContourFilter>::New();
      contourFilter->SetInputConnection(implicitModeller->GetOutputPort());
      contourFilter->SetValue(0, xrange/30.0); // 30% of xrange

      // Visualize
      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();

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

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

      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(contourFilter->GetOutputPort());
      mapper->ScalarVisibilityOff();

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);
      renderer->AddActor(actor);
      renderer->SetBackground(.1, .2, .3);

      renderWindow->Render();
      interactor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(ImplicitModeller)

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

    add_executable(ImplicitModeller MACOSX_BUNDLE ImplicitModeller.cxx)

    target_link_libraries(ImplicitModeller ${VTK_LIBRARIES})

### Download and Build ImplicitModeller

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

    cd ImplicitModeller/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:

    ./ImplicitModeller

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.