BluntStreamlines

VTKExamples/Cxx/VisualizationAlgorithms/BluntStreamlines


Description

This example shows airflow around a blunt fin. This example consists of a wall with half a rounded fin projecting into the fluid flow. (Using arguments of symmetry, only half of the domain was modeled.) Twenty-five streamlines are released upstream of the fin. The boundary layer effects near the junction of the fin and wall are clearly evident from the streamlines. In this area, flow recirculation is apparent, as well as the reduced flow speed.

Other Languages

See (Python)

Question

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Code

BluntStreamlines.cxx

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkLineSource.h>
#include <vtkMultiBlockDataSet.h>
#include <vtkMultiBlockPLOT3DReader.h>
#include <vtkNamedColors.h>
#include <vtkPointData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkStreamTracer.h>
#include <vtkStructuredGrid.h>
#include <vtkStructuredGridGeometryFilter.h>
#include <vtkStructuredGridOutlineFilter.h>

int main(int argc, char* argv[])
{
  if (argc != 3)
  {
    std::cout << "Usage: " << argv[0] << " bluntfinxyz.bin bluntfinq.bin"
              << std::endl;
    return EXIT_FAILURE;
  }

  double range[2], c[3];
  double maxTime = 0.0;

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

  auto aren =
    vtkSmartPointer<vtkRenderer>::New();
  auto renWin =
    vtkSmartPointer<vtkRenderWindow>::New();
  renWin->AddRenderer(aren);
  auto iren =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  iren->SetRenderWindow(renWin);

  std::string xyzFilename = argv[1];
  std::string qFilename = argv[2];

  auto reader =
    vtkSmartPointer<vtkMultiBlockPLOT3DReader>::New();
  reader->SetXYZFileName(xyzFilename.c_str());
  reader->SetQFileName(qFilename.c_str());
  reader->Update(); // force a read to occur

  vtkStructuredGrid* pd =
      dynamic_cast<vtkStructuredGrid*>(reader->GetOutput()->GetBlock(0));
  pd->GetCenter(c);
  if (pd->GetPointData()->GetScalars())
  {
    pd->GetPointData()->GetScalars()->GetRange(range);
  }
  if (pd->GetPointData()->GetVectors())
  {
    auto maxVelocity = pd->GetPointData()->GetVectors()->GetMaxNorm();
    maxTime = 20.0 * pd->GetLength() / maxVelocity;
  }

  auto outlineF =
    vtkSmartPointer<vtkStructuredGridOutlineFilter>::New();
  outlineF->SetInputData(pd);

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

  auto outline =
    vtkSmartPointer<vtkActor>::New();
  outline->SetMapper(outlineMapper);
  outline->GetProperty()->SetColor(colors->GetColor3d("Moccasin").GetData());
  outline->GetProperty()->SetLineWidth(2.0);

  //
  // Some geometry for context
  //
  auto wall =
    vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();
  wall->SetInputData(pd);
  wall->SetExtent(0, 100, 0, 100, 0, 0);

  auto wallMap =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  wallMap->SetInputConnection(wall->GetOutputPort());
  wallMap->ScalarVisibilityOff();

  auto wallActor =
    vtkSmartPointer<vtkActor>::New();
  wallActor->SetMapper(wallMap);
  wallActor->GetProperty()->SetColor(colors->GetColor3d("Silver").GetData());

  auto fin =
    vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();
  fin->SetInputData(pd);
  fin->SetExtent(0, 100, 0, 0, 0, 100);

  auto finMap =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  finMap->SetInputConnection(fin->GetOutputPort());
  finMap->ScalarVisibilityOff();

  auto finActor =
    vtkSmartPointer<vtkActor>::New();
  finActor->SetMapper(finMap);
  finActor->GetProperty()->SetColor(colors->GetColor3d("Silver").GetData());
  //
  // regular streamlines
  //
  auto line1 =
    vtkSmartPointer<vtkLineSource>::New();
  line1->SetResolution(25);
  line1->SetPoint1(-6.36, 0.25, 0.06);
  line1->SetPoint2(-6.36, 0.25, 5.37);

  auto rakeMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  rakeMapper->SetInputConnection(line1->GetOutputPort());

  auto rake1 =
    vtkSmartPointer<vtkActor>::New();
  rake1->SetMapper(rakeMapper);
  rake1->GetProperty()->SetColor(0.0, 0.0, 0.0);
  rake1->GetProperty()->SetLineWidth(5);

  auto streamers =
    vtkSmartPointer<vtkStreamTracer>::New();
  //  streamers->DebugOn();
  streamers->SetInputConnection(reader->GetOutputPort());
  streamers->SetSourceConnection(line1->GetOutputPort());
  streamers->SetMaximumPropagation(maxTime);
  streamers->SetInitialIntegrationStep(.2);
  streamers->SetMinimumIntegrationStep(.01);
  streamers->SetIntegratorType(2);
  streamers->Update();

  auto streamersMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  streamersMapper->SetInputConnection(streamers->GetOutputPort());
  streamersMapper->SetScalarRange(range);

  auto lines =
    vtkSmartPointer<vtkActor>::New();
  lines->SetMapper(streamersMapper);

  aren->AddActor(outline);
  aren->AddActor(wallActor);
  aren->AddActor(finActor);
  aren->AddActor(rake1);
  aren->AddActor(lines);
  aren->SetBackground(0.5, 0.5, 0.5);

  aren->ResetCamera();
  aren->GetActiveCamera()->Elevation(30.0);
  aren->GetActiveCamera()->Azimuth(30.0);
  aren->GetActiveCamera()->Dolly(1.2);
  aren->ResetCameraClippingRange();

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

  // interact with data
  iren->Start();

  // Clean up

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(BluntStreamlines)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersCore
  vtkFiltersFlowPaths
  vtkFiltersGeometry
  vtkFiltersSources
  vtkIOParallel
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping BluntStreamlines: ${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(BluntStreamlines MACOSX_BUNDLE BluntStreamlines.cxx )
  target_link_libraries(BluntStreamlines PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(BluntStreamlines MACOSX_BUNDLE BluntStreamlines.cxx )
  target_link_libraries(BluntStreamlines PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS BluntStreamlines
    MODULES ${VTK_LIBRARIES}
    )
endif () 

Download and Build BluntStreamlines

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

cd BluntStreamlines/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:

./BluntStreamlines

WINDOWS USERS

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