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UnsignedDistance

vtk-examples/Cxx/Points/UnsignedDistance


Description

Contrast this with the SignedDistance example.

The image was created using the Armadillo dataset, src/Testing/Data/Armadillo.ply.

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

UnsignedDistance.cxx

#include <vtkCamera.h>
#include <vtkImageActor.h>
#include <vtkImageData.h>
#include <vtkImageMapToColors.h>
#include <vtkImageMapper3D.h>
#include <vtkLookupTable.h>
#include <vtkMinimalStandardRandomSequence.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPointSource.h>
#include <vtkPolyData.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkScalarBarActor.h>
#include <vtkSmartPointer.h>
#include <vtkUnsignedDistance.h>

// Readers
#include <vtkBYUReader.h>
#include <vtkOBJReader.h>
#include <vtkPLYReader.h>
#include <vtkPolyDataReader.h>
#include <vtkSTLReader.h>
#include <vtkXMLPolyDataReader.h>

#include <algorithm> // For transform()
#include <cctype>    // For to_lower
#include <string>    // For find_last_of()

namespace {
vtkSmartPointer<vtkPolyData> ReadPolyData(std::string const& fileName);
}

int main(int argc, char* argv[])
{
  vtkNew<vtkNamedColors> colors;

  auto 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;
  // auto radius = range[0] * .02;
  auto radius = range[0] / static_cast<double>(dimension) * 5;
  ; // ~5 voxels
  std::cout << "Radius: " << radius << std::endl;
  vtkNew<vtkUnsignedDistance> distance;
  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).
  auto aboveRangeColor = colors->GetColor4d("White").GetData();
  aboveRangeColor[3] = 0.2;
  vtkNew<vtkLookupTable> hueLut;
  hueLut->SetTableRange(-.99 * radius, .99 * radius);
  hueLut->SetHueRange(.667, 0);
  hueLut->SetSaturationRange(1, 1);
  hueLut->SetValueRange(1, 1);
  hueLut->UseAboveRangeColorOn();
  hueLut->SetAboveRangeColor(aboveRangeColor);
  hueLut->SetNumberOfColors(5);
  hueLut->Build();
  double* last = hueLut->GetTableValue(4);
  hueLut->SetAboveRangeColor(last[0], last[1], last[2], 0);

  vtkNew<vtkImageMapToColors> sagittalColors;
  sagittalColors->SetInputConnection(distance->GetOutputPort());
  sagittalColors->SetLookupTable(hueLut);
  sagittalColors->Update();

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

  vtkNew<vtkImageMapToColors> axialColors;
  axialColors->SetInputConnection(distance->GetOutputPort());
  axialColors->SetLookupTable(hueLut);
  axialColors->Update();

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

  vtkNew<vtkImageMapToColors> coronalColors;
  coronalColors->SetInputConnection(distance->GetOutputPort());
  coronalColors->SetLookupTable(hueLut);
  coronalColors->Update();

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

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

  // Create graphics stuff
  //
  vtkNew<vtkRenderer> ren1;
  ren1->SetBackground(.3, .4, .6);

  vtkNew<vtkRenderWindow> renWin;
  renWin->AddRenderer(ren1);
  renWin->SetSize(600, 400);
  renWin->SetWindowName("UnsignedDistance");

  vtkNew<vtkRenderWindowInteractor> iren;
  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);
  ren1->SetBackground(colors->GetColor3d("CornflowerBlue").GetData());

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

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

  return EXIT_SUCCESS;
}

namespace {
vtkSmartPointer<vtkPolyData> ReadPolyData(std::string const& fileName)
{
  vtkSmartPointer<vtkPolyData> polyData;
  std::string extension = "";
  if (fileName.find_last_of(".") != std::string::npos)
  {
    extension = fileName.substr(fileName.find_last_of("."));
  }
  // Make the extension lowercase
  std::transform(extension.begin(), extension.end(), extension.begin(),
                 ::tolower);
  if (extension == ".ply")
  {
    vtkNew<vtkPLYReader> reader;
    reader->SetFileName(fileName.c_str());
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".vtp")
  {
    vtkNew<vtkXMLPolyDataReader> reader;
    reader->SetFileName(fileName.c_str());
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".vtk")
  {
    vtkNew<vtkPolyDataReader> reader;
    reader->SetFileName(fileName.c_str());
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".obj")
  {
    vtkNew<vtkOBJReader> reader;
    reader->SetFileName(fileName.c_str());
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".stl")
  {
    vtkNew<vtkSTLReader> reader;
    reader->SetFileName(fileName.c_str());
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".g")
  {
    vtkNew<vtkBYUReader> reader;
    reader->SetGeometryFileName(fileName.c_str());
    reader->Update();
    polyData = reader->GetOutput();
  }
  else
  {
    vtkNew<vtkMinimalStandardRandomSequence> randomSequence;
    randomSequence->SetSeed(8775070);

    vtkNew<vtkPointSource> points;
    points->SetNumberOfPoints(100000);
    points->SetRadius(10.0);
    double x, y, z;
    // random position
    x = randomSequence->GetRangeValue(-100, 100);
    randomSequence->Next();
    y = randomSequence->GetRangeValue(-100, 100);
    randomSequence->Next();
    z = randomSequence->GetRangeValue(-100, 100);
    randomSequence->Next();
    points->SetCenter(x, y, z);
    points->SetDistributionToShell();
    points->Update();
    polyData = points->GetOutput();
  }
  return polyData;
}

} // namespace

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(UnsignedDistance)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersPoints
  vtkFiltersSources
  vtkIOGeometry
  vtkIOLegacy
  vtkIOPLY
  vtkIOXML
  vtkImagingCore
  vtkInteractionStyle
  vtkRenderingAnnotation
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping UnsignedDistance: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(UnsignedDistance MACOSX_BUNDLE UnsignedDistance.cxx )
  target_link_libraries(UnsignedDistance PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(UnsignedDistance MACOSX_BUNDLE UnsignedDistance.cxx )
  target_link_libraries(UnsignedDistance PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS UnsignedDistance
    MODULES ${VTK_LIBRARIES}
    )
endif ()

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.