VTK/Examples/Cxx/Graphs/NOVCAGraph

• This example shows how to construct a graph to visualize it in ParaView/VisIt using the VTK output file testVertex.vtu.
• Contributed by Sanjaya Gajurel, Case Western Reserve University

NOVCAGraph.cxx

#include <vtkVersion.h>
#include <vtkCellArray.h>
#include <vtkPoints.h>
#include <vtkPolyLine.h>
#include <vtkTriangle.h>
#include <vtkXMLPolyDataWriter.h>
#include <vtkPolyData.h>
#include <vtkUnstructuredGrid.h>
#include <vtkXMLUnstructuredGridWriter.h>
#include <vtkSmartPointer.h>

int main ( int, char *[] )
{
  // Create 8 Vertices.
  vtkSmartPointer<vtkPoints> points =
    vtkSmartPointer<vtkPoints>::New();

  for ( unsigned int i = 0; i < 2; ++i )
     for ( unsigned int j = 0; j < 4; ++j )
          points->InsertNextPoint( i, j, 0);

   //Create Edges
    vtkSmartPointer<vtkPolyLine> line =
    vtkSmartPointer<vtkPolyLine>::New();
    line->GetPointIds()->SetNumberOfIds(8);
  for ( unsigned int i = 0; i < 8; ++i )
      line->GetPointIds()->SetId(i,i);

   vtkSmartPointer<vtkCellArray> cellArray =
    vtkSmartPointer<vtkCellArray>::New();
   cellArray->InsertNextCell(line);

  // Create a Graph with Vertices and Edges.
  vtkSmartPointer<vtkUnstructuredGrid> grid =
    vtkSmartPointer<vtkUnstructuredGrid>::New();
  grid->SetPoints(points);
  grid->SetCells(VTK_POLY_LINE,cellArray);

  // Write the file
  vtkSmartPointer<vtkXMLUnstructuredGridWriter> writer =
    vtkSmartPointer<vtkXMLUnstructuredGridWriter>::New();
  writer->SetFileName("testVertex.vtu");
#if VTK_MAJOR_VERSION <= 5
  writer->SetInput(grid);
#else
  writer->SetInputData(grid);
#endif

  writer->Write();

  return EXIT_SUCCESS;
}

Please try the new VTKExamples website.

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(NOVCAGraph)

find_package(VTK REQUIRED)
include(${VTK_USE_FILE})

add_executable(NOVCAGraph MACOSX_BUNDLE NOVCAGraph.cxx)

if(VTK_LIBRARIES)
  target_link_libraries(NOVCAGraph ${VTK_LIBRARIES})
else()
  target_link_libraries(NOVCAGraph vtkHybrid vtkWidgets)
endif()

Download and Build NOVCAGraph

Click here to download NOVCAGraph. and its CMakeLists.txt file.

Once the tarball NOVCAGraph.tar has been downloaded and extracted,

cd NOVCAGraph/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:

./NOVCAGraph

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.