# HyperStreamline

VTKExamples/Cxx/VisualizationAlgorithms/HyperStreamline

### Description

This is an example of hyperstreamlines. The data is from a point load applied to semi-infinite domain. Compare this image to TensorEllipsoids that used tensor ellipsoids to visualize the same data. Notice that there is less clutter and more information available from the hyperstreamline visualization.

Info

See Figure 9-15 in Chapter 9 The VTK Textbook.

Other Languages

See (Python)

### Code

HyperStreamline.cxx

    #include <vtkActor.h>
    #include <vtkCamera.h>
    #include <vtkConeSource.h>
    #include <vtkHyperStreamline.h>
    #include <vtkImageData.h>
    #include <vtkImageDataGeometryFilter.h>
    #include <vtkLogLookupTable.h>
    #include <vtkNamedColors.h>
    #include <vtkOutlineFilter.h>
    #include <vtkPointLoad.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>

    int main (int, char *[])
    {
    // Create the RenderWindow, Renderer and interactive renderer
    //
      vtkSmartPointer<vtkNamedColors> colors =
        vtkSmartPointer<vtkNamedColors>::New();

      vtkSmartPointer<vtkRenderer> ren1 =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renWin =
        vtkSmartPointer<vtkRenderWindow>::New();
      renWin->SetMultiSamples(0);
      renWin->AddRenderer(ren1);

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

    //set VTK_INTEGRATE_BOTH_DIRECTIONS 2

    //
    // generate tensors
      vtkSmartPointer<vtkPointLoad> ptLoad =
        vtkSmartPointer<vtkPointLoad>::New();
      ptLoad->SetLoadValue(100.0);
      ptLoad->SetSampleDimensions(20, 20, 20);
      ptLoad->ComputeEffectiveStressOn();
      ptLoad->SetModelBounds(-10, 10, -10, 10, -10, 10);
      ptLoad->Update();

    // Generate hyperstreamlines
      vtkSmartPointer<vtkHyperStreamline> s1 =
        vtkSmartPointer<vtkHyperStreamline>::New();
      s1->SetInputData(ptLoad->GetOutput());
      s1->SetStartPosition(9, 9, -9);
      s1->IntegrateMinorEigenvector();
      s1->SetMaximumPropagationDistance(18.0);
      s1->SetIntegrationStepLength(0.1);
      s1->SetStepLength(0.01);
      s1->SetRadius(0.25);
      s1->SetNumberOfSides(18);
      s1->SetIntegrationDirectionToIntegrateBothDirections();
      s1->Update();

    // Map hyperstreamlines
      vtkSmartPointer<vtkLogLookupTable> lut =
        vtkSmartPointer<vtkLogLookupTable>::New();
      lut->SetHueRange(.6667, 0.0);

      vtkSmartPointer<vtkPolyDataMapper> s1Mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      s1Mapper->SetInputConnection(s1->GetOutputPort());
      s1Mapper->SetLookupTable(lut);
      s1Mapper->SetScalarRange(ptLoad->GetOutput()->GetScalarRange());

      vtkSmartPointer<vtkActor> s1Actor =
        vtkSmartPointer<vtkActor>::New();
      s1Actor->SetMapper(s1Mapper);

      vtkSmartPointer<vtkHyperStreamline> s2 =
        vtkSmartPointer<vtkHyperStreamline>::New();
      s2->SetInputData(ptLoad->GetOutput());
      s2->SetStartPosition(-9, -9, -9);
      s2->IntegrateMinorEigenvector();
      s2->SetMaximumPropagationDistance(18.0);
      s2->SetIntegrationStepLength(0.1);
      s2->SetStepLength(0.01);
      s2->SetRadius(0.25);
      s2->SetNumberOfSides(18);
      s2->SetIntegrationDirectionToIntegrateBothDirections();
      s2->Update();

      vtkSmartPointer<vtkPolyDataMapper> s2Mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      s2Mapper->SetInputConnection(s2->GetOutputPort());
      s2Mapper->SetLookupTable(lut);
      s2Mapper->SetScalarRange(ptLoad->GetOutput()->GetScalarRange());

      vtkSmartPointer<vtkActor> s2Actor =
        vtkSmartPointer<vtkActor>::New();
      s2Actor->SetMapper(s2Mapper);

      vtkSmartPointer<vtkHyperStreamline> s3 =
        vtkSmartPointer<vtkHyperStreamline>::New();
      s3->SetInputData(ptLoad->GetOutput());
      s3->SetStartPosition(9, -9, -9);
      s3->IntegrateMinorEigenvector();
      s3->SetMaximumPropagationDistance(18.0);
      s3->SetIntegrationStepLength(0.1);
      s3->SetStepLength(0.01);
      s3->SetRadius(0.25);
      s3->SetNumberOfSides(18);
      s3->SetIntegrationDirectionToIntegrateBothDirections();
      s3->Update();

      vtkSmartPointer<vtkPolyDataMapper> s3Mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      s3Mapper->SetInputConnection(s3->GetOutputPort());
      s3Mapper->SetLookupTable(lut);
      s3Mapper->SetScalarRange(ptLoad->GetOutput()->GetScalarRange());

      vtkSmartPointer<vtkActor> s3Actor =
        vtkSmartPointer<vtkActor>::New();
      s3Actor->SetMapper(s3Mapper);

      vtkSmartPointer<vtkHyperStreamline> s4 =
        vtkSmartPointer<vtkHyperStreamline>::New();
      s4->SetInputData(ptLoad->GetOutput());
      s4->SetStartPosition(-9, 9, -9);
      s4->IntegrateMinorEigenvector();
      s4->SetMaximumPropagationDistance(18.0);
      s4->SetIntegrationStepLength(0.1);
      s4->SetStepLength(0.01);
      s4->SetRadius(0.25);
      s4->SetNumberOfSides(18);
      s4->SetIntegrationDirectionToIntegrateBothDirections();
      s4->Update();

      vtkSmartPointer<vtkPolyDataMapper> s4Mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      s4Mapper->SetInputConnection(s4->GetOutputPort());
      s4Mapper->SetLookupTable(lut);
      s4Mapper->SetScalarRange(ptLoad->GetOutput()->GetScalarRange());

      vtkSmartPointer<vtkActor> s4Actor =
        vtkSmartPointer<vtkActor>::New();
      s4Actor->SetMapper(s4Mapper);

    // plane for context
    //
      vtkSmartPointer<vtkImageDataGeometryFilter> g =
        vtkSmartPointer<vtkImageDataGeometryFilter>::New();
      g->SetInputData(ptLoad->GetOutput());
      g->SetExtent(0, 100, 0, 100, 0, 0);
      g->Update(); //for scalar range

      vtkSmartPointer<vtkPolyDataMapper> gm =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      gm->SetInputConnection(g->GetOutputPort());
      gm->SetScalarRange(g->GetOutput()->GetScalarRange());

      vtkSmartPointer<vtkActor> ga =
        vtkSmartPointer<vtkActor>::New();
      ga->SetMapper(gm);

    // Create outline around data
    //
      vtkSmartPointer<vtkOutlineFilter> outline =
        vtkSmartPointer<vtkOutlineFilter>::New();
      outline->SetInputData(ptLoad->GetOutput());

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

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

    // Create cone indicating application of load
    //
      vtkSmartPointer<vtkConeSource> coneSrc =
        vtkSmartPointer<vtkConeSource>::New();
      coneSrc->SetRadius(.5);
      coneSrc->SetHeight(2);

      vtkSmartPointer<vtkPolyDataMapper> coneMap =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      coneMap->SetInputConnection(coneSrc->GetOutputPort());

      vtkSmartPointer<vtkActor> coneActor =
        vtkSmartPointer<vtkActor>::New();
      coneActor->SetMapper(coneMap);
      coneActor->SetPosition(0, 0, 11);
      coneActor->RotateY(90);
      coneActor->GetProperty()->SetColor(colors->GetColor3d("Tomato").GetData());

      vtkSmartPointer<vtkCamera> camera =
        vtkSmartPointer<vtkCamera>::New();
      camera->SetFocalPoint(0.113766, -1.13665, -1.01919);
      camera->SetPosition(-29.4886, -63.1488, 26.5807);
      camera->SetViewAngle(24.4617);
      camera->SetViewUp(0.17138, 0.331163, 0.927879);
      camera->SetClippingRange(1, 100);

      ren1->AddActor(s1Actor);
      ren1->AddActor(s2Actor);
      ren1->AddActor(s3Actor);
      ren1->AddActor(s4Actor);
      ren1->AddActor(outlineActor);
      ren1->AddActor(coneActor);
      ren1->AddActor(ga);
      ren1->SetBackground(colors->GetColor3d("SlateGray").GetData());
      ren1->SetActiveCamera(camera);

      renWin->SetSize(640, 480);
      renWin->Render();
      iren->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(HyperStreamline)

    find_package(VTK COMPONENTS
      vtkCommonColor
      vtkCommonDataModel
      vtkFiltersGeneral
      vtkFiltersGeometry
      vtkFiltersModeling
      vtkFiltersSources
      vtkImagingHybrid
      vtkInteractionStyle
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping HyperStreamline: ${VTK_NOT_FOUND_MESSAGE}")
      return ()
    endif()
    message (STATUS "VTK_VERSION: ${VTK_VERSION}")
    if (VTK_VERSION VERSION_LESS "8.90.0")
      # old system
      include(${VTK_USE_FILE})
      add_executable(HyperStreamline MACOSX_BUNDLE HyperStreamline.cxx )
      target_link_libraries(HyperStreamline PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(HyperStreamline MACOSX_BUNDLE HyperStreamline.cxx )
      target_link_libraries(HyperStreamline PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS HyperStreamline
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build HyperStreamline

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

    cd HyperStreamline/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:

    ./HyperStreamline

WINDOWS USERS

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