SurfaceFromUnorganizedPointsWithPostProc

VTKExamples/Cxx/Filtering/SurfaceFromUnorganizedPointsWithPostProc

Description

This example is an extension to the example previously posted at: Create a surface from Unorganized Points

The objective is again to use vtkSurfaceReconstructionFilter to construct a surface from a set of points. However, the direct output of the vtkSurfaceReconstructionFilter does not match with the spatial position of the original point set. Instead, there is a scale change and translation in between. To cure this, in this example we added a post transformation to move the reconstructed surface back to the position of the original points, which in some cases might be more favorable.

Code

SurfaceFromUnorganizedPointsWithPostProc.cxx

#include <vtkSurfaceReconstructionFilter.h>
#include <vtkSmartPointer.h>

#include <vtkNamedColors.h>
#include <vtkProgrammableSource.h>
#include <vtkContourFilter.h>
#include <vtkReverseSense.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkPolyData.h>
#include <vtkCamera.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkMath.h>
#include <cmath>

#include <vtkTransform.h>
#include <vtkTransformPolyDataFilter.h>

#include <vtkSphereSource.h>
#include <vtkXMLPolyDataReader.h>

namespace
{
static vtkSmartPointer<vtkPolyData> transform_back(vtkSmartPointer<vtkPoints> pt, vtkSmartPointer<vtkPolyData> pd);
}

int main(int argc, char *argv[])
{
  vtkSmartPointer<vtkNamedColors> namedColors =
    vtkSmartPointer<vtkNamedColors>::New();

  vtkSmartPointer<vtkPolyData> input;
  if(argc > 1)
  {
    vtkSmartPointer<vtkXMLPolyDataReader> reader =
      vtkSmartPointer<vtkXMLPolyDataReader>::New();
    reader->SetFileName(argv[1]);
    reader->Update();
    input = reader->GetOutput();
  }
  else
  {
    vtkSmartPointer<vtkSphereSource> sphereSource =
      vtkSmartPointer<vtkSphereSource>::New();
    sphereSource->Update();
    input = sphereSource->GetOutput();
  }
  // Read some points
  vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();

  vtkSmartPointer<vtkPolyData> polydata = vtkSmartPointer<vtkPolyData>::New();
  polydata->SetPoints(input->GetPoints());

  // Construct the surface and create isosurface.   
  vtkSmartPointer<vtkSurfaceReconstructionFilter> surf =
    vtkSmartPointer<vtkSurfaceReconstructionFilter>::New();
  surf->SetInputData(polydata);

  vtkSmartPointer<vtkContourFilter> contourFilter = vtkSmartPointer<vtkContourFilter>::New();
  contourFilter->SetInputConnection(surf->GetOutputPort());
  contourFilter->SetValue(0, 0.0);


  // Sometimes the contouring algorithm can create a volume whose gradient
  // vector and ordering of polygon (using the right hand rule) are
  // inconsistent. vtkReverseSense cures this problem.
  vtkSmartPointer<vtkReverseSense> reverse = vtkSmartPointer<vtkReverseSense>::New();
  reverse->SetInputConnection(contourFilter->GetOutputPort());
  reverse->ReverseCellsOn();
  reverse->ReverseNormalsOn();
  reverse->Update();

  vtkSmartPointer<vtkPolyData> newSurf = transform_back( points, reverse->GetOutput());

  vtkSmartPointer<vtkPolyDataMapper> map = vtkSmartPointer<vtkPolyDataMapper>::New();
  map->SetInputConnection(reverse->GetOutputPort());
  map->ScalarVisibilityOff();

  vtkSmartPointer<vtkActor> surfaceActor = vtkSmartPointer<vtkActor>::New();
  surfaceActor->SetMapper(map);
  surfaceActor->GetProperty()->SetDiffuseColor(
    namedColors->GetColor3d("Tomato").GetData());
  surfaceActor->GetProperty()->SetSpecularColor(namedColors->GetColor3d("Seashell").GetData());
  surfaceActor->GetProperty()->SetSpecular(.4);
  surfaceActor->GetProperty()->SetSpecularPower(50);

  // Create the RenderWindow, Renderer and both Actors
  vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> interactor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  interactor->SetRenderWindow(renderWindow);

  // Add the actors to the renderer, set the background and size
  renderer->AddActor(surfaceActor);
  renderer->SetBackground(namedColors->GetColor3d("Burlywood").GetData());
  renderWindow->SetSize(640, 480);

  interactor->Initialize();
  renderWindow->Render();
  interactor->Start();

  return EXIT_SUCCESS;
}


namespace
{
vtkSmartPointer<vtkPolyData> transform_back(vtkSmartPointer<vtkPoints> pt, vtkSmartPointer<vtkPolyData> pd)
{
  // The reconstructed surface is transformed back to where the
  // original points are. (Hopefully) it is only a similarity
  // transformation.

  // 1. Get bounding box of pt, get its minimum corner (left, bottom, least-z), at c0, pt_bounds

  // 2. Get bounding box of surface pd, get its minimum corner (left, bottom, least-z), at c1, pd_bounds

  // 3. compute scale as:
  //       scale = (pt_bounds[1] - pt_bounds[0])/(pd_bounds[1] - pd_bounds[0]);

  // 4. transform the surface by T := T(pt_bounds[0], [2], [4]).S(scale).T(-pd_bounds[0], -[2], -[4])


  // 1.
  double pt_bounds[6];  // (xmin,xmax, ymin,ymax, zmin,zmax)
  pt->GetBounds(pt_bounds);

  // 2.
  double pd_bounds[6];  // (xmin,xmax, ymin,ymax, zmin,zmax)
  pd->GetBounds(pd_bounds);

//   // test, make sure it is isotropic
//   std::cout<<(pt_bounds[1] - pt_bounds[0])/(pd_bounds[1] - pd_bounds[0])<<std::endl;
//   std::cout<<(pt_bounds[3] - pt_bounds[2])/(pd_bounds[3] - pd_bounds[2])<<std::endl;
//   std::cout<<(pt_bounds[5] - pt_bounds[4])/(pd_bounds[5] - pd_bounds[4])<<std::endl;
//   // TEST

  // 3
  double scale = (pt_bounds[1] - pt_bounds[0])/(pd_bounds[1] - pd_bounds[0]);

  // 4.
  vtkSmartPointer<vtkTransform> transp = vtkSmartPointer<vtkTransform>::New();
  transp->Translate(pt_bounds[0], pt_bounds[2], pt_bounds[4]);
  transp->Scale(scale, scale, scale);
  transp->Translate(- pd_bounds[0], - pd_bounds[2], - pd_bounds[4]);

  vtkSmartPointer<vtkTransformPolyDataFilter> tpd = vtkSmartPointer<vtkTransformPolyDataFilter>::New();

  tpd->SetInputData(pd);
  tpd->SetTransform(transp);
  tpd->Update();


  return tpd->GetOutput();
}
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(SurfaceFromUnorganizedPointsWithPostProc)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkCommonTransforms
  vtkFiltersCore
  vtkFiltersGeneral
  vtkFiltersSources
  vtkIOXML
  vtkImagingHybrid
  vtkInteractionStyle
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping SurfaceFromUnorganizedPointsWithPostProc: ${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(SurfaceFromUnorganizedPointsWithPostProc MACOSX_BUNDLE SurfaceFromUnorganizedPointsWithPostProc.cxx )
  target_link_libraries(SurfaceFromUnorganizedPointsWithPostProc PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(SurfaceFromUnorganizedPointsWithPostProc MACOSX_BUNDLE SurfaceFromUnorganizedPointsWithPostProc.cxx )
  target_link_libraries(SurfaceFromUnorganizedPointsWithPostProc PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS SurfaceFromUnorganizedPointsWithPostProc
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build SurfaceFromUnorganizedPointsWithPostProc

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

cd SurfaceFromUnorganizedPointsWithPostProc/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:

./SurfaceFromUnorganizedPointsWithPostProc

WINDOWS USERS

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