UnsignedDistance

VTKExamples/Cxx/Points/UnsignedDistance


Description

Contrast this with the SignedDistance example.

The image was created using the Armadillo dataset

Warning

The classes used in this example require vtk 7.1 or later.

Code

UnsignedDistance.cxx

#include <vtkSmartPointer.h>
#include <vtkPLYReader.h>
#include <vtkXMLPolyDataReader.h>
#include <vtkOBJReader.h>
#include <vtkSTLReader.h>
#include <vtkPointSource.h>

#include <vtkUnsignedDistance.h>
#include <vtkImageMapToColors.h>
#include <vtkLookupTable.h>
#include <vtkImageData.h>

#include <vtkImageActor.h>
#include <vtkScalarBarActor.h>

#include <vtkImageMapper3D.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkCamera.h>

#include <vtksys/SystemTools.hxx>

static vtkSmartPointer<vtkPolyData> ReadPolyData(const char *fileName);

int main (int argc, char *argv[])
{
  vtkSmartPointer<vtkPolyData> polyData = ReadPolyData(argc > 1 ? argv[1] : "");;

  double bounds[6];
  polyData->GetBounds(bounds);
  double range[3];
  for (int i = 0; i < 3; ++i)
  {
    range[i] = bounds[2*i + 1] - bounds[2*i];
  }

  int sampleSize = polyData->GetNumberOfPoints() * .00005;
  if (sampleSize < 10)
  {
    sampleSize = 10;
  }
  std::cout << "Sample size is: " << sampleSize << std::endl;
  std::cout << "Range: "
            << range[0] << ", "
            << range[1] << ", "
            << range[2] << std::endl;
  int dimension = 256;
  dimension = 128;
  double radius = range[0] * .02;
  radius = range[0] / static_cast<double>(dimension) * 5;; // ~5 voxels
  std::cout << "Radius: " << radius << std::endl;
  vtkSmartPointer<vtkUnsignedDistance> distance =
    vtkSmartPointer<vtkUnsignedDistance>::New();
  distance->SetInputData (polyData);
  distance->SetRadius(radius);
  distance->SetDimensions(dimension, dimension, dimension);
  distance->SetBounds(
    bounds[0] - range[0] * .1,
    bounds[1] + range[0] * .1,
    bounds[2] - range[1] * .1,
    bounds[3] + range[1] * .1,
    bounds[4] - range[2] * .1,
    bounds[5] + range[2] * .1);

  // Create a lookup table that consists of the full hue circle
  // (from HSV).
  vtkSmartPointer<vtkLookupTable> hueLut =
    vtkSmartPointer<vtkLookupTable>::New();
  hueLut->SetTableRange (-.99 * radius, .99 * radius);
  hueLut->SetHueRange (.667, 0);
  hueLut->SetSaturationRange (1, 1);
  hueLut->SetValueRange (1, 1);
  hueLut->UseAboveRangeColorOn();
  hueLut->SetAboveRangeColor(0, 0, 0, 0);
  hueLut->SetNumberOfColors(5);
  hueLut->Build();
  double *last = hueLut->GetTableValue(4);
  hueLut->SetAboveRangeColor(last[0], last[1], last[2], 0);

  vtkSmartPointer<vtkImageMapToColors> sagittalColors =
    vtkSmartPointer<vtkImageMapToColors>::New();
  sagittalColors->SetInputConnection(distance->GetOutputPort());
  sagittalColors->SetLookupTable(hueLut);
  sagittalColors->Update();

  vtkSmartPointer<vtkImageActor> sagittal =
    vtkSmartPointer<vtkImageActor>::New();
  sagittal->GetMapper()->SetInputConnection(sagittalColors->GetOutputPort());
  sagittal->SetDisplayExtent(dimension/2, dimension/2, 0, dimension - 1, 0, dimension - 1);
  sagittal->ForceOpaqueOn();

  vtkSmartPointer<vtkImageMapToColors> axialColors =
    vtkSmartPointer<vtkImageMapToColors>::New();
  axialColors->SetInputConnection(distance->GetOutputPort());
  axialColors->SetLookupTable(hueLut);
  axialColors->Update();

  vtkSmartPointer<vtkImageActor> axial =
    vtkSmartPointer<vtkImageActor>::New();
  axial->GetMapper()->SetInputConnection(axialColors->GetOutputPort());
  axial->SetDisplayExtent(0, dimension - 1, 0, dimension - 1, dimension/2, dimension/2);
  axial->ForceOpaqueOn();

  vtkSmartPointer<vtkImageMapToColors> coronalColors =
    vtkSmartPointer<vtkImageMapToColors>::New();
  coronalColors->SetInputConnection(distance->GetOutputPort());
  coronalColors->SetLookupTable(hueLut);
  coronalColors->Update();

  vtkSmartPointer<vtkImageActor> coronal =
    vtkSmartPointer<vtkImageActor>::New();
  coronal->GetMapper()->SetInputConnection(coronalColors->GetOutputPort());
  coronal->SetDisplayExtent(0, dimension - 1, dimension/2, dimension/2, 0, dimension - 1);
  coronal->ForceOpaqueOn();

  // Create a scalar bar
  vtkSmartPointer<vtkScalarBarActor> scalarBar =
    vtkSmartPointer<vtkScalarBarActor>::New();
  scalarBar->SetLookupTable(hueLut);
  scalarBar->SetTitle("Distance");
  scalarBar->SetNumberOfLabels(5);

  // Create graphics stuff
  //
  vtkSmartPointer<vtkRenderer> ren1 =
    vtkSmartPointer<vtkRenderer>::New();
  ren1->SetBackground(.3, .4, .6);

  vtkSmartPointer<vtkRenderWindow> renWin =
    vtkSmartPointer<vtkRenderWindow>::New();
  renWin->AddRenderer(ren1);
  renWin->SetSize(512,512);

  vtkSmartPointer<vtkRenderWindowInteractor> iren =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  iren->SetRenderWindow(renWin);

  // Add the actors to the renderer, set the background and size
  //
  ren1->AddActor(sagittal);
  ren1->AddActor(axial);
  ren1->AddActor(coronal);
  ren1->AddActor2D(scalarBar);

  // Generate an interesting view
  //
  ren1->ResetCamera();
  ren1->GetActiveCamera()->Azimuth(120);
  ren1->GetActiveCamera()->Elevation(30);
  ren1->GetActiveCamera()->Dolly(1.5);
  ren1->ResetCameraClippingRange();

  iren->Initialize();
  iren->Start();
  std::cout << distance->GetOutput()->GetScalarRange()[0] << ", "
            << distance->GetOutput()->GetScalarRange()[1] << std::endl;
  return EXIT_SUCCESS;
}

static vtkSmartPointer<vtkPolyData> ReadPolyData(const char *fileName)
{
  vtkSmartPointer<vtkPolyData> polyData;
  std::string extension = vtksys::SystemTools::GetFilenameExtension(std::string(fileName));
  if (extension == ".ply")
  {
    vtkSmartPointer<vtkPLYReader> reader =
      vtkSmartPointer<vtkPLYReader>::New();
    reader->SetFileName (fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".vtp")
  {
    vtkSmartPointer<vtkXMLPolyDataReader> reader =
      vtkSmartPointer<vtkXMLPolyDataReader>::New();
    reader->SetFileName (fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".obj")
  {
    vtkSmartPointer<vtkOBJReader> reader =
      vtkSmartPointer<vtkOBJReader>::New();
    reader->SetFileName (fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".stl")
  {
    vtkSmartPointer<vtkSTLReader> reader =
      vtkSmartPointer<vtkSTLReader>::New();
    reader->SetFileName (fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else
  {
    vtkSmartPointer<vtkPointSource> points =
      vtkSmartPointer<vtkPointSource>::New();
    points->SetNumberOfPoints(100000);
    points->SetRadius(10.0);
    points->SetCenter(vtkMath::Random(-100, 100),
                      vtkMath::Random(-100, 100),
                      vtkMath::Random(-100, 100));
    points->SetDistributionToShell();
    points->Update();
    polyData = points->GetOutput();
  }
  return polyData;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(UnsignedDistance)

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

add_executable(UnsignedDistance MACOSX_BUNDLE UnsignedDistance.cxx )

target_link_libraries(UnsignedDistance ${VTK_LIBRARIES})

Download and Build UnsignedDistance

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

cd UnsignedDistance/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:

./UnsignedDistance

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.