VTK/Examples/TriangleSolidColor

#include <vtkSmartPointer.h>
#include <vtkPoints.h>
#include <vtkXMLPolyDataWriter.h>
#include <vtkPolyData.h>
#include <vtkCellData.h>
#include <vtkCellArray.h>
#include <vtkTriangle.h>
 
int main(int argc, char *argv[])
{		
  //setup points
  vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
  vtkSmartPointer<vtkCellArray> vertices = vtkSmartPointer<vtkCellArray>::New();
  points->InsertNextPoint(1.0, 0.0, 0.0);
  points->InsertNextPoint(0.0, 0.0, 1.0);
  points->InsertNextPoint(0.0, 0.0, 0.0);
 
  //setup colors
  unsigned char red[3] = {255, 0, 0};
 
  vtkSmartPointer<vtkUnsignedCharArray> colors = vtkSmartPointer<vtkUnsignedCharArray>::New();
  colors->SetNumberOfComponents(3);
  colors->SetName("Colors");
  colors->InsertNextTupleValue(red);
 
  vtkSmartPointer<vtkCellArray> triangles = vtkSmartPointer<vtkCellArray>::New();
  vtkSmartPointer<vtkTriangle> triangle = vtkSmartPointer<vtkTriangle>::New();
  triangle->GetPointIds()->SetId(0, 0);
  triangle->GetPointIds()->SetId(1, 1);
  triangle->GetPointIds()->SetId(2, 2);
  triangles->InsertNextCell(triangle);
 
  vtkSmartPointer<vtkPolyData> polydata = vtkSmartPointer<vtkPolyData>::New();
 
  polydata->SetPoints(points);
  polydata->SetPolys(triangles);
  polydata->GetCellData()->AddArray(colors);
 
  vtkSmartPointer<vtkXMLPolyDataWriter> writer = vtkSmartPointer<vtkXMLPolyDataWriter>::New();
  writer->SetFileName("TriangleSolidColor.vtp");
  writer->SetInput(polydata);
  writer->Write();
 
  return 0;
}