VTK/Tutorials/TriangleGeometryOnly

This example writes the coordinates of the corners of a triangle to a vtp file. There is geometry (points), but there is no topology (vertices), so if you open this file in Paraview, you will not see anything. You can "glyph" the points to see them, but generally some type of topology exists. We will see topology in the next example.

TrianglePoints.cxx

<source lang="cpp">

1. include <vtkSmartPointer.h>
2. include <vtkPoints.h>
3. include <vtkXMLPolyDataWriter.h>
4. include <vtkPolyData.h>

int main(int argc, char *argv[]) {

 //create a set of points
 vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
 points->InsertNextPoint ( 1.0, 0.0, 0.0 );
 points->InsertNextPoint ( 0.0, 0.0, 0.0 );
 points->InsertNextPoint ( 0.0, 1.0, 0.0 );

 //create a polydata
 vtkSmartPointer<vtkPolyData> polydata = vtkSmartPointer<vtkPolyData>::New();

 //add the points to the polydata
 polydata->SetPoints ( points );

 //write the polydata to a file
 vtkSmartPointer<vtkXMLPolyDataWriter> writer = vtkSmartPointer<vtkXMLPolyDataWriter>::New();
 writer->SetFileName ( "TrianglePoints.vtp" );

1. if VTK_MAJOR_VERSION <= 5

 writer->SetInput( polydata );

1. else

 writer->SetInputData( polydata );
#endif
 writer->Write();

 return EXIT_SUCCESS;

}

</source>

CMakeLists.txt

<source lang="cmake"> cmake_minimum_required(VERSION 2.6)

project(TrianglePoints)

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

add_executable(TrianglePoints TrianglePoints.cxx) if(VTK_LIBRARIES)

 target_link_libraries(TrianglePoints ${VTK_LIBRARIES})

else()

 target_link_libraries(TrianglePoints vtkHybrid)

endif()

</source>