BluntStreamlines
VTKEx/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.
Info
See Figure 6-19 in Chapter 6 the VTK Textbook.
Other languages
See (Python)
Question
If you have a simple question about this example contact us at VTKExProject If your question is more complex and may require extended discussion, please use the VTK Discourse Forum
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
vtkvtkCommonColor
vtkvtkCommonCore
vtkvtkCommonDataModel
vtkvtkFiltersCore
vtkvtkFiltersFlowPaths
vtkvtkFiltersGeometry
vtkvtkFiltersSources
vtkvtkIOParallel
vtkvtkInteractionStyle
vtkvtkRenderingContextOpenGL2
vtkvtkRenderingCore
vtkvtkRenderingFreeType
vtkvtkRenderingGL2PSOpenGL2
vtkvtkRenderingOpenGL2 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.