# OverlappingAMR

VTKExamples/Cxx/CompositeData/OverlappingAMR

### Code

OverlappingAMR.cxx

    //Demonstrates how to create and populate a VTK's Overlapping AMR Grid type Data

    #include <vtkAMRBox.h>
    #include <vtkAMRUtilities.h>
    #include <vtkContourFilter.h>
    #include <vtkFloatArray.h>
    #include <vtkCompositeDataGeometryFilter.h>
    #include <vtkOutlineFilter.h>
    #include <vtkOverlappingAMR.h>
    #include <vtkPointData.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkSmartPointer.h>
    #include <vtkSphere.h>
    #include <vtkUniformGrid.h>

    namespace
    {
      void MakeScalars(int dims[3], double origin[3], double spacing[3],
          vtkFloatArray* scalars)
      {
        // Implicit function used to compute scalars
        vtkSmartPointer<vtkSphere> sphere = vtkSmartPointer<vtkSphere>::New();
        sphere->SetRadius(3);
        sphere->SetCenter(5, 5, 5);

        scalars->SetNumberOfTuples(dims[0]*dims[1]*dims[2]);
        for (int k=0; k<dims[2]; k++)
        {
          double z = origin[2] + spacing[2]*k;
          for (int j=0; j<dims[1]; j++)
          {
            double y = origin[1] + spacing[1]*j;
            for (int i=0; i<dims[0]; i++)
            {
              double x = origin[0] + spacing[0]*i;
              scalars->SetValue(
                  k*dims[0]*dims[1] + j*dims[0] + i,
                  sphere->EvaluateFunction(x, y, z));
            }
          }
        }
      }
    }

    int main (int, char *[])
    {
      // Create and populate the AMR dataset
      // The dataset should look like
      // Level 0
      //   uniform grid, dimensions 11, 11, 11, AMR box (0, 0, 0) - (9, 9, 9)
      // Level 1 - refinement ratio : 2
      //   uniform grid, dimensions 11, 11, 11, AMR box (0, 0, 0) - (9, 9, 9)
      //   uniform grid, dimensions 11, 11, 11, AMR box (10, 10, 10) - (19, 19, 19)
      // Use MakeScalars() above to fill the scalar arrays

      vtkSmartPointer<vtkOverlappingAMR> amr =
        vtkSmartPointer<vtkOverlappingAMR>::New();
      int blocksPerLevel[] = { 1, 2 };
      amr->Initialize(2, blocksPerLevel);

      double origin[3] = {0.0, 0.0, 0.0};
      double spacing[3] = {1.0, 1.0, 1.0};
      int dims[3] = {11, 11, 11};

      vtkSmartPointer<vtkUniformGrid> ug1 = vtkSmartPointer<vtkUniformGrid>::New();
      // Geometry
      ug1->SetOrigin(origin);
      ug1->SetSpacing(spacing);
      ug1->SetDimensions(dims);

      // Data
      vtkSmartPointer<vtkFloatArray> scalars =
        vtkSmartPointer<vtkFloatArray>::New();
      ug1->GetPointData()->SetScalars(scalars);
      MakeScalars(dims, origin, spacing, scalars);

      int lo[3] = {0, 0, 0};
      int hi[3] = {9, 9, 9};
      vtkAMRBox box1(lo, hi);
      amr->SetAMRBox(0, 0, box1);
      amr->SetDataSet(0, 0, ug1);

      double spacing2[3] = {0.5, 0.5, 0.5};

      vtkSmartPointer<vtkUniformGrid> ug2 = vtkSmartPointer<vtkUniformGrid>::New();
      // Geometry
      ug2->SetOrigin(origin);
      ug2->SetSpacing(spacing2);
      ug2->SetDimensions(dims);

      // Data
      scalars = vtkSmartPointer<vtkFloatArray>::New();
      ug2->GetPointData()->SetScalars(scalars);
      MakeScalars(dims, origin, spacing2, scalars);

      int lo2[3] = {0, 0, 0};
      int hi2[3] = {9, 9, 9};
      vtkAMRBox box2(lo2, hi2);
      amr->SetAMRBox(1, 0, box2);
      amr->SetDataSet(1, 0, ug2);

      double origin3[3] = {5, 5, 5};

      vtkSmartPointer<vtkUniformGrid> ug3 = vtkSmartPointer<vtkUniformGrid>::New();
      // Geometry
      ug3->SetOrigin(origin3);
      ug3->SetSpacing(spacing2);
      ug3->SetDimensions(dims);

      // Data
      scalars = vtkSmartPointer<vtkFloatArray>::New();
      ug3->GetPointData()->SetScalars(scalars);
      MakeScalars(dims, origin3, spacing2, scalars);

      int lo3[3] = {10, 10, 10};
      int hi3[3] = {19, 19, 19};
      vtkAMRBox box3(lo3, hi3);
      amr->SetAMRBox(1, 1, box3);
      amr->SetDataSet(1, 1, ug3);

      amr->SetRefinementRatio(0, 2);
      vtkAMRUtilities::BlankCells(amr);

      // Render the amr data here
      vtkSmartPointer<vtkOutlineFilter> of =
        vtkSmartPointer<vtkOutlineFilter>::New();
      of->SetInputData(amr);

      vtkSmartPointer<vtkCompositeDataGeometryFilter> geomFilter =
        vtkSmartPointer<vtkCompositeDataGeometryFilter>::New();
      geomFilter->SetInputConnection(of->GetOutputPort());

      // Create an iso-surface - at 10
      vtkSmartPointer<vtkContourFilter> cf =
        vtkSmartPointer<vtkContourFilter>::New();
      cf->SetInputData(amr);
      cf->SetNumberOfContours(1);
      cf->SetValue(0, 10.0);

      vtkSmartPointer<vtkCompositeDataGeometryFilter> geomFilter2 =
        vtkSmartPointer<vtkCompositeDataGeometryFilter>::New();
      geomFilter2->SetInputConnection(cf->GetOutputPort());

      // create the render window, renderer, and interactor
      vtkSmartPointer<vtkRenderer> aren = vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renWin  =
        vtkSmartPointer<vtkRenderWindow>::New();
      renWin->AddRenderer(aren);

      vtkSmartPointer<vtkRenderWindowInteractor> iren =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      iren->SetRenderWindow(renWin);

      // associate the geometry with a mapper and the mapper to an actor
      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();

      mapper->SetInputConnection(geomFilter->GetOutputPort());

      vtkActor *actor1 = vtkActor::New();
      actor1->SetMapper(mapper);

      // associate the geometry with a mapper and the mapper to an actor
      vtkSmartPointer<vtkPolyDataMapper> mapper2 =
        vtkSmartPointer<vtkPolyDataMapper>::New();

      mapper2->SetInputConnection(geomFilter2->GetOutputPort());

      vtkActor *actor2 = vtkActor::New();
      actor2->SetMapper(mapper2);

      // add the actor to the renderer and start handling events
      aren->AddActor(actor1);
      aren->AddActor(actor2);
      renWin->Render();
      iren->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(OverlappingAMR)

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

    add_executable(OverlappingAMR MACOSX_BUNDLE OverlappingAMR.cxx)

    target_link_libraries(OverlappingAMR ${VTK_LIBRARIES})

### Download and Build OverlappingAMR

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

    cd OverlappingAMR/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:

    ./OverlappingAMR

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.