TensorGlyph
VTKExamples/Cxx/Visualization/TensorGlyph
Description
This example demonstrates how to apply a rotation+scaling matrix to each point in a data set. We use a cube as the glyph so that simple rotations are easy to interpret. Specifically, we glyph one point with no rotation/scaling, and a second point with a rotation of 45 degrees around the x axis.
Code
TensorGlyph.cxx
#include <vtkVersion.h>
#include <vtkActor.h>
#include <vtkCellArray.h>
#include <vtkDoubleArray.h>
#include <vtkMath.h>
#include <vtkPointData.h>
#include <vtkPoints.h>
#include <vtkPointSource.h>
#include <vtkPolyDataMapper.h>
#include <vtkPolyData.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSmartPointer.h>
#include <vtkCubeSource.h>
#include <vtkTensorGlyph.h>
#include <vtkVertexGlyphFilter.h>
int main(int, char *[])
{
// Setup points
vtkSmartPointer<vtkPoints> points =
vtkSmartPointer<vtkPoints>::New();
points->InsertNextPoint(0.0, 0.0, 0.0);
points->InsertNextPoint(5.0, 0.0, 0.0);
vtkSmartPointer<vtkPolyData> polyData = vtkSmartPointer<vtkPolyData>::New();
polyData->SetPoints(points);
vtkSmartPointer<vtkDoubleArray> tensors = vtkSmartPointer<vtkDoubleArray>::New();
tensors->SetNumberOfTuples(2);
tensors->SetNumberOfComponents(9);
tensors->InsertTuple9(0,1,0,0,0,1,0,0,0,1);
tensors->InsertTuple9(1,1,0,0,0,.7,.7,0,-.7,.7); // column major
polyData->GetPointData()->SetTensors(tensors);
vtkSmartPointer<vtkCubeSource> cubeSource = vtkSmartPointer<vtkCubeSource>::New();
cubeSource->Update();
vtkSmartPointer<vtkTensorGlyph> tensorGlyph = vtkSmartPointer<vtkTensorGlyph>::New();
#if VTK_MAJOR_VERSION <= 5
tensorGlyph->SetInput(polyData);
#else
tensorGlyph->SetInputData(polyData);
#endif
tensorGlyph->SetSourceConnection(cubeSource->GetOutputPort());
tensorGlyph->ColorGlyphsOff();
tensorGlyph->ThreeGlyphsOff();
tensorGlyph->ExtractEigenvaluesOff();
tensorGlyph->Update();
vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
#if VTK_MAJOR_VERSION <= 5
mapper->SetInput(tensorGlyph->GetOutput());
#else
mapper->SetInputData(tensorGlyph->GetOutput());
#endif
vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
renderer->AddActor(actor);
vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->AddRenderer( renderer );
vtkSmartPointer<vtkRenderWindowInteractor> interactor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
interactor->SetRenderWindow( renderWindow );
renderWindow->Render();
interactor->Start();
return 0;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(TensorGlyph)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(TensorGlyph MACOSX_BUNDLE TensorGlyph.cxx)
target_link_libraries(TensorGlyph ${VTK_LIBRARIES})
Download and Build TensorGlyph
Click here to download TensorGlyph and its CMakeLists.txt file. Once the tarball TensorGlyph.tar has been downloaded and extracted,
cd TensorGlyph/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:
./TensorGlyph
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.