# LOxGrid

VTKExamples/Cxx/VisualizationAlgorithms/LOxGrid

### Desription

Portion of computational grid for the LOx post.

Info

See Figure 12-14 in Chapter 12 the VTK Textbook.

Other Languages

See (Python)

### Code

LOxGrid.cxx

    #include <vtkActor.h>
    #include <vtkCamera.h>
    #include <vtkLookupTable.h>
    #include <vtkMultiBlockDataSet.h>
    #include <vtkMultiBlockPLOT3DReader.h>
    #include <vtkNamedColors.h>
    #include <vtkPointSource.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkProperty.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkStreamTracer.h>
    #include <vtkStructuredGrid.h>
    #include <vtkStructuredGridGeometryFilter.h>
    #include <vtkStructuredGridOutlineFilter.h>
    #include <vtkTubeFilter.h>

    //// LOx post CFD case study

    int main (int argc, char *argv[])
    {
      if (argc < 3)
      {
        std::cout << "Usage: " << argv[0] << " postxyz.bin postq.bin" << std::endl;
        return EXIT_FAILURE;
      }
    // read data
    //
      vtkSmartPointer<vtkMultiBlockPLOT3DReader> pl3d =
        vtkSmartPointer<vtkMultiBlockPLOT3DReader>::New();
      pl3d->AutoDetectFormatOn();
      pl3d->SetXYZFileName(argv[1]);
      pl3d->SetQFileName(argv[2]);
      pl3d->SetScalarFunctionNumber(153);
      pl3d->SetVectorFunctionNumber(200);
      pl3d->Update();

      vtkStructuredGrid *sg =
        vtkStructuredGrid::SafeDownCast(pl3d->GetOutput()->GetBlock(0));

      vtkSmartPointer<vtkNamedColors> colors =
        vtkSmartPointer<vtkNamedColors>::New();

    //blue to red lut
    //
      vtkSmartPointer<vtkLookupTable> lut =
        vtkSmartPointer<vtkLookupTable>::New();
      lut->SetHueRange(0.667, 0.0);

    // computational planes
      vtkSmartPointer<vtkStructuredGridGeometryFilter> floorComp =
        vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();
      floorComp->SetExtent(0, 37, 0, 75, 0, 0);
      floorComp->SetInputData(sg);
      floorComp->Update();

      vtkSmartPointer<vtkPolyDataMapper> floorMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      floorMapper->SetInputConnection(floorComp->GetOutputPort());
      floorMapper->ScalarVisibilityOff();
      floorMapper->SetLookupTable(lut);

      vtkSmartPointer<vtkActor> floorActor =
        vtkSmartPointer<vtkActor>::New();
      floorActor->SetMapper(floorMapper);
      floorActor->GetProperty()->SetRepresentationToWireframe();
      floorActor->GetProperty()->SetColor(colors->GetColor3d("Beige").GetData());
      floorActor->GetProperty()->SetLineWidth(2);

      vtkSmartPointer<vtkStructuredGridGeometryFilter> subFloorComp =
        vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();

      subFloorComp->SetExtent(0, 37, 0, 15, 22, 22);
      subFloorComp->SetInputData(sg);

      vtkSmartPointer<vtkPolyDataMapper> subFloorMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      subFloorMapper->SetInputConnection(subFloorComp->GetOutputPort());
      subFloorMapper->SetLookupTable(lut);
      subFloorMapper->SetScalarRange(sg->GetScalarRange());

      vtkSmartPointer<vtkActor> subFloorActor =
        vtkSmartPointer<vtkActor>::New();

      subFloorActor->SetMapper(subFloorMapper);

      vtkSmartPointer<vtkStructuredGridGeometryFilter> subFloor2Comp =
        vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();
      subFloor2Comp->SetExtent(0, 37, 60, 75, 22, 22);
      subFloor2Comp->SetInputData(sg);

      vtkSmartPointer<vtkPolyDataMapper> subFloor2Mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      subFloor2Mapper->SetInputConnection(subFloor2Comp->GetOutputPort());
      subFloor2Mapper->SetLookupTable(lut);
      subFloor2Mapper->SetScalarRange(sg->GetScalarRange());

      vtkSmartPointer<vtkActor> subFloor2Actor =
        vtkSmartPointer<vtkActor>::New();

      subFloor2Actor->SetMapper(subFloor2Mapper);

      vtkSmartPointer<vtkStructuredGridGeometryFilter> postComp =
        vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();

      postComp->SetExtent(10, 10, 0, 75, 0, 37);
      postComp->SetInputData(sg);

      vtkSmartPointer<vtkPolyDataMapper> postMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      postMapper->SetInputConnection(postComp->GetOutputPort());
      postMapper->SetLookupTable(lut);
      postMapper->SetScalarRange(sg->GetScalarRange());

      vtkSmartPointer<vtkActor> postActor =
        vtkSmartPointer<vtkActor>::New();
      postActor->SetMapper(postMapper);
      postActor->GetProperty()->SetColor(colors->GetColor3d("Beige").GetData());

      vtkSmartPointer<vtkStructuredGridGeometryFilter> fanComp =
        vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();
      fanComp->SetExtent(0, 37, 38, 38, 0, 37);
      fanComp->SetInputData(sg);

      vtkSmartPointer<vtkPolyDataMapper> fanMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      fanMapper->SetInputConnection(fanComp->GetOutputPort());
      fanMapper->SetLookupTable(lut);
      fanMapper->SetScalarRange(sg->GetScalarRange());

      vtkSmartPointer<vtkActor> fanActor =
        vtkSmartPointer<vtkActor>::New();

      fanActor->SetMapper(fanMapper);
      fanActor->GetProperty()->SetColor(colors->GetColor3d("Beige").GetData());

    // streamers
    //
    // spherical seed points
      vtkSmartPointer<vtkPointSource> rake =
        vtkSmartPointer<vtkPointSource>::New();
      rake->SetCenter(-0.74, 0, 0.3);
      rake->SetNumberOfPoints(10);

    // a line of seed points
      vtkSmartPointer<vtkStructuredGridGeometryFilter> seedsComp =
        vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();
      seedsComp->SetExtent(10, 10, 37, 39, 1, 35);
      seedsComp->SetInputData(sg);

      vtkSmartPointer<vtkStreamTracer> streamers =
        vtkSmartPointer<vtkStreamTracer>::New();
      streamers->SetInputConnection(pl3d->GetOutputPort());

    //    streamers SetSource [rake GetOutput]
      streamers->SetSourceConnection(seedsComp->GetOutputPort());
      streamers->SetMaximumPropagation(250);
      streamers->SetInitialIntegrationStep(.2);
      streamers->SetMinimumIntegrationStep(.01);
      streamers->SetIntegratorType(2);
      streamers->Update();

      vtkSmartPointer<vtkTubeFilter> tubes =
        vtkSmartPointer<vtkTubeFilter>::New();
      tubes->SetInputConnection(streamers->GetOutputPort());
      tubes->SetNumberOfSides(8);
      tubes->SetRadius(.08);
      tubes->SetVaryRadius(0);

      vtkSmartPointer<vtkPolyDataMapper> mapTubes =
        vtkSmartPointer<vtkPolyDataMapper>::New();

      mapTubes->SetInputConnection(tubes->GetOutputPort());
      mapTubes->SetScalarRange(sg->GetScalarRange());

      vtkSmartPointer<vtkActor> tubesActor =
        vtkSmartPointer<vtkActor>::New();
      tubesActor->SetMapper(mapTubes);

    // outline
      vtkSmartPointer<vtkStructuredGridOutlineFilter> outline =
        vtkSmartPointer<vtkStructuredGridOutlineFilter>::New();
      outline->SetInputData(sg);

      vtkSmartPointer<vtkPolyDataMapper> outlineMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      outlineMapper->SetInputConnection(outline->GetOutputPort());

      vtkSmartPointer<vtkActor> outlineActor =
        vtkSmartPointer<vtkActor>::New();
      outlineActor->SetMapper(outlineMapper);
      outlineActor->GetProperty()->SetColor(colors->GetColor3d("Beige").GetData());

    // Create graphics stuff
      vtkSmartPointer<vtkRenderer> ren1 =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renWin =
        vtkSmartPointer<vtkRenderWindow>::New();
      renWin->AddRenderer(ren1);

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

    // Add the actors to the renderer, set the background and size
    //
      ren1->AddActor(outlineActor);
      ren1->AddActor(floorActor);
      ren1->AddActor(subFloorActor);
      ren1->AddActor(subFloor2Actor);
      ren1->AddActor(postActor);
      ren1->AddActor(fanActor);
      ren1->AddActor(tubesActor);

      vtkSmartPointer<vtkCamera> aCam =
        vtkSmartPointer<vtkCamera>::New();
      aCam->SetFocalPoint(0.00657892, 0, 2.41026);
      aCam->SetPosition(-1.94838, -47.1275, 39.4607);
      aCam->SetViewUp(0.00653193, 0.617865, 0.786257);
      ren1->ResetCamera();
      aCam->Dolly(1.);
      aCam->SetClippingRange(1, 100);

      ren1->SetBackground(colors->GetColor3d("SlateGray").GetData());
      ren1->SetActiveCamera(aCam);
      renWin->SetSize(640, 480);

      renWin->Render();
      iren->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(LOxGrid)

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

    add_executable(LOxGrid MACOSX_BUNDLE LOxGrid.cxx )

    target_link_libraries(LOxGrid ${VTK_LIBRARIES})

### Download and Build LOxGrid

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

    cd LOxGrid/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:

    ./LOxGrid

WINDOWS USERS

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