StreamLines

VTKEx/Cxx/Visualization/StreamLines

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

StreamLines.cxx

#include <vtkSmartPointer.h>

#include <vtkStreamTracer.h>

#include <vtkNamedColors.h>
#include <vtkActor.h>
#include <vtkMultiBlockPLOT3DReader.h>
#include <vtkMultiBlockDataSet.h>
#include <vtkPlaneSource.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkStructuredGridOutlineFilter.h>
#include <vtkProperty.h>

int main(int argc, char *argv[])
{
  if(argc < 3)
  {
    std::cerr << "Required arguments: xyzFile qFile" << std::endl;
    return EXIT_FAILURE;
  }

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

  std::string xyzFile = argv[1]; // "combxyz.bin";
  std::string qFile = argv[2]; // "combq.bin";

  vtkSmartPointer<vtkMultiBlockPLOT3DReader> pl3d =
    vtkSmartPointer<vtkMultiBlockPLOT3DReader>::New();
  pl3d->SetXYZFileName(xyzFile.c_str());
  pl3d->SetQFileName(qFile.c_str());
  pl3d->SetScalarFunctionNumber(100);
  pl3d->SetVectorFunctionNumber(202);
  pl3d->Update();

  // Source of the streamlines
  vtkSmartPointer<vtkPlaneSource> seeds = 
    vtkSmartPointer<vtkPlaneSource>::New();
  seeds->SetXResolution(4);
  seeds->SetYResolution(4);
  seeds->SetOrigin(2,-2,26);
  seeds->SetPoint1(2,2,26);
  seeds->SetPoint2(2,-2,32);

  // Streamline itself
  vtkSmartPointer<vtkStreamTracer> streamLine = 
    vtkSmartPointer<vtkStreamTracer>::New();
  pl3d->Update();
  streamLine->SetInputData(pl3d->GetOutput()->GetBlock(0));
  streamLine->SetSourceConnection(seeds->GetOutputPort());
  streamLine->SetMaximumPropagation(100);
  streamLine->SetInitialIntegrationStep(0.1);
  streamLine->SetIntegrationDirectionToBoth();

  //streamLine->SetStartPosition(2,-2,30);
  // as alternative to the SetSource(), which can handle multiple
  // streamlines, you can set a SINGLE streamline from
  // SetStartPosition()

  vtkSmartPointer<vtkPolyDataMapper> streamLineMapper = 
    vtkSmartPointer<vtkPolyDataMapper>::New();
  streamLineMapper->SetInputConnection(streamLine->GetOutputPort());

  vtkSmartPointer<vtkActor> streamLineActor = 
    vtkSmartPointer<vtkActor>::New();
  streamLineActor->SetMapper(streamLineMapper);
  streamLineActor->VisibilityOn();

  // Outline-Filter for the grid
  vtkSmartPointer<vtkStructuredGridOutlineFilter> outline = 
    vtkSmartPointer<vtkStructuredGridOutlineFilter>::New();
  outline->SetInputData(pl3d->GetOutput()->GetBlock(0));

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

  vtkSmartPointer<vtkActor> outlineActor = 
    vtkSmartPointer<vtkActor>::New();
  outlineActor->SetMapper(outlineMapper);
  outlineActor->GetProperty()->SetColor(1, 1, 1);

  // Create the RenderWindow, Renderer and Actors
  vtkSmartPointer<vtkRenderer> renderer = 
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow = 
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);

  vtkSmartPointer<vtkRenderWindowInteractor> interactor = 
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  interactor->SetRenderWindow(renderWindow);

  vtkSmartPointer<vtkInteractorStyleTrackballCamera> style = 
    vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New();
  interactor->SetInteractorStyle(style);

  renderer->AddActor(streamLineActor);
  renderer->AddActor(outlineActor);

  // Add the actors to the renderer, set the background and size
  renderer->SetBackground(namedColors->GetColor3d("Cadet").GetData());
  renderWindow->SetSize(300, 300);
  interactor->Initialize();
  renderWindow->Render();

  interactor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(StreamLines)

find_package(VTK COMPONENTS 
  vtkvtkCommonColor
  vtkvtkCommonCore
  vtkvtkCommonDataModel
  vtkvtkFiltersCore
  vtkvtkFiltersFlowPaths
  vtkvtkFiltersSources
  vtkvtkIOParallel
  vtkvtkInteractionStyle
  vtkvtkRenderingContextOpenGL2
  vtkvtkRenderingCore
  vtkvtkRenderingFreeType
  vtkvtkRenderingGL2PSOpenGL2
  vtkvtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping StreamLines: ${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(StreamLines MACOSX_BUNDLE StreamLines.cxx )
  target_link_libraries(StreamLines PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(StreamLines MACOSX_BUNDLE StreamLines.cxx )
  target_link_libraries(StreamLines PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS StreamLines
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build StreamLines

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

cd StreamLines/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:

./StreamLines

WINDOWS USERS

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