Delaunay3D

VTKExamples/Cxx/Modelling/Delaunay3D

Description

This example creates a tetrahedral mesh from unorganized points. The example uses the vtkDelaunay3D filter. The resulting mesh will be a solid convex hull of the original points. The example takes the points from a XML PolyData file (.vtp) produces the 3D Delaunay tetrahedralization (both with alpha = 0 and a non-zero alpha), and displays the result on the screen.

Code

Delaunay3D.cxx

#include <vtkCellArray.h>
#include <vtkProperty.h>
#include <vtkDataSetMapper.h>
#include <vtkActor.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolygon.h>
#include <vtkSmartPointer.h>
#include <vtkMath.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkCleanPolyData.h>
#include <vtkDelaunay3D.h>
#include <vtkXMLPolyDataReader.h>

int main ( int argc, char *argv[] )
{
  if(argc < 2)
  {
    std::cout << "Usage: " << argv[0]
              << " filename.vtp" << std::endl;
    return EXIT_FAILURE;
  }

  //Read the file
  vtkSmartPointer<vtkXMLPolyDataReader> reader =
    vtkSmartPointer<vtkXMLPolyDataReader>::New();
  reader->SetFileName(argv[1]);

  vtkSmartPointer<vtkDataSetMapper> originalMapper =
    vtkSmartPointer<vtkDataSetMapper>::New();
  originalMapper->SetInputConnection(reader->GetOutputPort());

  vtkSmartPointer<vtkActor> originalActor =
    vtkSmartPointer<vtkActor>::New();
  originalActor->SetMapper(originalMapper);
  originalActor->GetProperty()->SetColor(1,0,0);

  // Clean the polydata. This will remove duplicate points that may be
  // present in the input data.
  vtkSmartPointer<vtkCleanPolyData> cleaner =
    vtkSmartPointer<vtkCleanPolyData>::New();
  cleaner->SetInputConnection (reader->GetOutputPort());

  // Generate a tetrahedral mesh from the input points. By
  // default, the generated volume is the convex hull of the points.
  vtkSmartPointer<vtkDelaunay3D> delaunay3D =
    vtkSmartPointer<vtkDelaunay3D>::New();
  delaunay3D->SetInputConnection (cleaner->GetOutputPort());

  vtkSmartPointer<vtkDataSetMapper> delaunayMapper =
    vtkSmartPointer<vtkDataSetMapper>::New();
  delaunayMapper->SetInputConnection(delaunay3D->GetOutputPort());

  vtkSmartPointer<vtkActor> delaunayActor =
    vtkSmartPointer<vtkActor>::New();
  delaunayActor->SetMapper(delaunayMapper);
  delaunayActor->GetProperty()->SetColor(1,0,0);

  // Generate a mesh from the input points. If Alpha is non-zero, then
  // tetrahedra, triangles, edges and vertices that lie within the
  // alpha radius are output.
  vtkSmartPointer<vtkDelaunay3D> delaunay3DAlpha =
    vtkSmartPointer<vtkDelaunay3D>::New();
  delaunay3DAlpha->SetInputConnection (cleaner->GetOutputPort());
  delaunay3DAlpha->SetAlpha(0.1);

  vtkSmartPointer<vtkDataSetMapper> delaunayAlphaMapper =
    vtkSmartPointer<vtkDataSetMapper>::New();
  delaunayAlphaMapper->SetInputConnection(delaunay3DAlpha->GetOutputPort());

  vtkSmartPointer<vtkActor> delaunayAlphaActor =
    vtkSmartPointer<vtkActor>::New();
  delaunayAlphaActor->SetMapper(delaunayAlphaMapper);
  delaunayAlphaActor->GetProperty()->SetColor(1,0,0);

  // Visualize

  // Define viewport ranges
  // (xmin, ymin, xmax, ymax)
  double leftViewport[4] = {0.0, 0.0, 0.33, 1.0};
  double centerViewport[4] = {0.33, 0.0, 0.66, 1.0};
  double rightViewport[4] = {0.66, 0.0, 1.0, 1.0};

  // Create a renderer, render window, and interactor
  vtkSmartPointer<vtkRenderer> originalRenderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderer> delaunayRenderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderer> delaunayAlphaRenderer =
    vtkSmartPointer<vtkRenderer>::New();

  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->SetSize(900,300);

  renderWindow->AddRenderer(originalRenderer);
  originalRenderer->SetViewport(leftViewport);
  renderWindow->AddRenderer(delaunayRenderer);
  delaunayRenderer->SetViewport(centerViewport);
  renderWindow->AddRenderer(delaunayAlphaRenderer);
  delaunayAlphaRenderer->SetViewport(rightViewport);

  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);

  originalRenderer->AddActor(originalActor);
  delaunayRenderer->AddActor(delaunayActor);
  delaunayAlphaRenderer->AddActor(delaunayAlphaActor);

  originalRenderer->SetBackground(.3, .6, .3);
  delaunayRenderer->SetBackground(.4, .6, .3);
  delaunayAlphaRenderer->SetBackground(.5, .6, .3);

  // Render and interact
  renderWindow->Render();
  renderWindowInteractor->Start();
  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(Delaunay3D)

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

add_executable(Delaunay3D MACOSX_BUNDLE Delaunay3D.cxx)

target_link_libraries(Delaunay3D ${VTK_LIBRARIES})

Download and Build Delaunay3D

Click here to download Delaunay3D and its CMakeLists.txt file. Once the tarball Delaunay3D.tar has been downloaded and extracted,

cd Delaunay3D/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:

./Delaunay3D

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.