# WarpCombustor

VTKExamples/Cxx/VisualizationAlgorithms/WarpCombustor

### Description

This example demonstrates how to extract "computational planes" from a structured dataset. Structured data has a natural, logical coordinate system based on i-j-k indices. Specifying imin,imax, jmin,jmax, kmin,kmax pairs can indicate a point, line, plane, or volume of data.

In this example, we extract three planes and warp them using scalar values in the direction of the local normal at each point. This gives a sort of "velocity profile" that indicates the nature of the flow.

### Code

WarpCombustor.cxx

    #include <vtkActor.h>
    #include <vtkAppendPolyData.h>
    #include <vtkCamera.h>
    #include <vtkMultiBlockDataSet.h>
    #include <vtkMultiBlockPLOT3DReader.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkPolyDataNormals.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>
    #include <vtkStructuredGrid.h>
    #include <vtkStructuredGridGeometryFilter.h>
    #include <vtkStructuredGridOutlineFilter.h>
    #include <vtkWarpScalar.h>

    #include <vtkNamedColors.h>

    // This example demonstrates how to extract "computational planes" from a
    // structured dataset. Structured data has a natural, logical coordinate
    // system based on i-j-k indices. Specifying imin,imax, jmin,jmax, kmin,kmax
    // pairs can indicate a point, line, plane, or volume of data.
    //
    // In this example, we extract three planes and warp them using scalar values
    // in the direction of the local normal at each point. This gives a sort of
    // "velocity profile" that indicates the nature of the flow.

    int main (int argc, char *argv[])
    {
      if (argc < 3)
      {
        std::cout << "Usage: " << argv[0] << " combxyz.bin combq.bin" << std::endl;
        return EXIT_FAILURE;
      }
      // Here we read data from a annular combustor. A combustor burns fuel and air
      // in a gas turbine (e.g., a jet engine) and the hot gas eventually makes its
      // way to the turbine section.
      //
      vtkSmartPointer<vtkMultiBlockPLOT3DReader> pl3d =
        vtkSmartPointer<vtkMultiBlockPLOT3DReader>::New();
      pl3d->SetXYZFileName(argv[1]);
      pl3d->SetQFileName(argv[2]);
      pl3d->SetScalarFunctionNumber(100);
      pl3d->SetVectorFunctionNumber(202);
      pl3d->Update();

      vtkStructuredGrid *pl3dOutput =
        vtkStructuredGrid::SafeDownCast(pl3d->GetOutput()->GetBlock(0));

      // Planes are specified using a imin,imax, jmin,jmax, kmin,kmax coordinate
      // specification. Min and max i,j,k values are clamped to 0 and maximum value.
      //
      vtkSmartPointer<vtkStructuredGridGeometryFilter> plane =
        vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();
      plane->SetInputData(pl3dOutput);
      plane->SetExtent(10, 10, 1, 100, 1, 100);

      vtkSmartPointer<vtkStructuredGridGeometryFilter> plane2 =
        vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();
      plane2->SetInputData(pl3dOutput);
      plane2->SetExtent(30, 30, 1, 100, 1, 100);
      vtkSmartPointer<vtkStructuredGridGeometryFilter> plane3 =
        vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();
      plane3->SetInputData(pl3dOutput);
      plane3->SetExtent(45, 45, 1, 100, 1, 100);

      // We use an append filter because that way we can do the warping, etc. just
      // using a single pipeline and actor.
      //
      vtkSmartPointer<vtkAppendPolyData> appendF =
        vtkSmartPointer<vtkAppendPolyData>::New();
      appendF->AddInputConnection(plane->GetOutputPort());
      appendF->AddInputConnection(plane2->GetOutputPort());
      appendF->AddInputConnection(plane3->GetOutputPort());

      vtkSmartPointer<vtkWarpScalar> warp =
        vtkSmartPointer<vtkWarpScalar>::New();
      warp->SetInputConnection(appendF->GetOutputPort());
      warp->UseNormalOn();
      warp->SetNormal(1.0, 0.0, 0.0);
      warp->SetScaleFactor(2.5);

      vtkSmartPointer<vtkPolyDataNormals> normals =
        vtkSmartPointer<vtkPolyDataNormals>::New();
      normals->SetInputConnection(warp->GetOutputPort());
      normals->SetFeatureAngle(60);

      vtkSmartPointer<vtkPolyDataMapper> planeMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      planeMapper->SetInputConnection(normals->GetOutputPort());
      planeMapper->SetScalarRange(pl3dOutput->GetScalarRange());

      vtkSmartPointer<vtkActor> planeActor =
        vtkSmartPointer<vtkActor>::New();
      planeActor->SetMapper(planeMapper);

      // The outline provides context for the data and the planes.
      vtkSmartPointer<vtkStructuredGridOutlineFilter> outline =
        vtkSmartPointer<vtkStructuredGridOutlineFilter>::New();
      outline->SetInputData(pl3dOutput);

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

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

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

      // Create the usual 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);

      ren1->AddActor(outlineActor);
      ren1->AddActor(planeActor);
      ren1->SetBackground(colors->GetColor3d("Silver").GetData());
      renWin->SetSize(640, 480);

    // Create an initial view.
      ren1->GetActiveCamera()->SetClippingRange(3.95297, 50);
      ren1->GetActiveCamera()->SetFocalPoint(8.88908, 0.595038, 29.3342);
      ren1->GetActiveCamera()->SetPosition(-12.3332, 31.7479, 41.2387);
      ren1->GetActiveCamera()->SetViewUp(0.060772, -0.319905, 0.945498);
      iren->Initialize();

    // render the image
    //
      renWin->Render();
      iren->Start();
      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(WarpCombustor)

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

    add_executable(WarpCombustor MACOSX_BUNDLE WarpCombustor.cxx )

    target_link_libraries(WarpCombustor ${VTK_LIBRARIES})

### Download and Build WarpCombustor

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

    cd WarpCombustor/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:

    ./WarpCombustor

WINDOWS USERS

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