VectorField
VTKExamples/Cxx/Visualization/VectorField
Code¶
VectorField.cxx
#include <vtkVersion.h> #include <vtkArrowSource.h> #include <vtkCellArray.h> #include <vtkGlyph2D.h> #include <vtkPointData.h> #include <vtkImageData.h> #include <vtkImageSliceMapper.h> #include <vtkImageSlice.h> #include <vtkInteractorStyleImage.h> #include <vtkPolyDataMapper.h> #include <vtkPolyData.h> #include <vtkPoints.h> #include <vtkRenderer.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkSmartPointer.h> #include <vtkXMLPolyDataWriter.h> int main(int, char *[]) { // Create an image vtkSmartPointer<vtkImageData> image = vtkSmartPointer<vtkImageData>::New(); // Specify the size of the image data image->SetDimensions(50,50,1); #if VTK_MAJOR_VERSION <= 5 image->SetNumberOfScalarComponents(2); image->SetScalarTypeToFloat(); image->AllocateScalars(); #else image->AllocateScalars(VTK_FLOAT,2); #endif int* dims = image->GetDimensions(); // Zero the image for (int y = 0; y < dims[1]; y++) { for (int x = 0; x < dims[0]; x++) { float* pixel = static_cast<float*>(image->GetScalarPointer(x,y,0)); pixel[0] = 0.0; pixel[1] = 0.0; } } { float* pixel = static_cast<float*>(image->GetScalarPointer(20,20,0)); pixel[0] = -10.0; pixel[1] = 5.0; } { float* pixel = static_cast<float*>(image->GetScalarPointer(30,30,0)); pixel[0] = 10.0; pixel[1] = 10.0; } // A better way to do this is (should be tested for compilablilty and correctness): // image->GetPointData()->SetActiveVectors(image->GetPointData()->GetScalars()->GetName().c_str()); image->GetPointData()->SetActiveVectors("ImageScalars"); // Setup the arrows vtkSmartPointer<vtkArrowSource> arrowSource = vtkSmartPointer<vtkArrowSource>::New(); arrowSource->Update(); vtkSmartPointer<vtkGlyph2D> glyphFilter = vtkSmartPointer<vtkGlyph2D>::New(); glyphFilter->SetSourceConnection(arrowSource->GetOutputPort()); glyphFilter->OrientOn(); glyphFilter->SetVectorModeToUseVector(); #if VTK_MAJOR_VERSION <= 5 glyphFilter->SetInputConnection(image->GetProducerPort()); #else glyphFilter->SetInputData(image); #endif glyphFilter->Update(); // Create actors vtkSmartPointer<vtkImageSliceMapper> imageMapper = vtkSmartPointer<vtkImageSliceMapper>::New(); #if VTK_MAJOR_VERSION <= 5 imageMapper->SetInputConnection(image->GetProducerPort()); #else imageMapper->SetInputData(image); #endif vtkSmartPointer<vtkImageSlice> imageSlice = vtkSmartPointer<vtkImageSlice>::New(); imageSlice->SetMapper(imageMapper); vtkSmartPointer<vtkPolyDataMapper> vectorMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); vectorMapper->SetInputConnection(glyphFilter->GetOutputPort()); vtkSmartPointer<vtkActor> vectorActor = vtkSmartPointer<vtkActor>::New(); vectorActor->SetMapper(vectorMapper); // Setup renderer vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New(); renderer->AddViewProp(imageSlice); renderer->AddViewProp(vectorActor); renderer->ResetCamera(); // Setup render window vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->AddRenderer(renderer); // Setup render window interactor vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New(); vtkSmartPointer<vtkInteractorStyleImage> style = vtkSmartPointer<vtkInteractorStyleImage>::New(); //renderWindowInteractor->SetInteractorStyle(style); // Render and start interaction renderWindowInteractor->SetRenderWindow(renderWindow); renderWindowInteractor->Initialize(); renderWindowInteractor->Start(); return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(VectorField) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(VectorField MACOSX_BUNDLE VectorField.cxx) target_link_libraries(VectorField ${VTK_LIBRARIES})
Download and Build VectorField¶
Danger
The generation of tar files has not been ported to the new VTKExamples. Some tarballs may be missing or out-of-date.
Click here to download VectorField and its CMakeLists.txt file. Once the tarball VectorField.tar has been downloaded and extracted,
cd VectorField/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:
./VectorField
WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.