FitImplicitFunction

VTKEx/Cxx/Points/FitImplicitFunction

Description

Warning

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

Other languages

See (Java)

Question

If you have a simple question about this example contact us at VTKExProject If your question is more complex and may require extended discussion, please use the VTK Discourse Forum

Code

FitImplicitFunction.cxx

#include <vtkSmartPointer.h>
#include <vtkFitImplicitFunction.h>
#include <vtkBoundedPointSource.h>

#include <vtkSphere.h>
#include <vtkSphereSource.h>
#include <vtkGlyph3D.h>
#include <vtkMath.h>

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

int main (int, char *[])
{
  vtkMath::RandomSeed(4355412); // for test result consistency

  double radius = 1.0;
  vtkSmartPointer<vtkBoundedPointSource> points =
    vtkSmartPointer<vtkBoundedPointSource>::New();
  points->SetNumberOfPoints(1000000);
  points->SetBounds(-2.0, 2.0, -2.0, 2.0, -2.0, 2.0);

  vtkSmartPointer<vtkSphere> sphere =
    vtkSmartPointer<vtkSphere>::New();
  sphere->SetRadius(radius);

  vtkSmartPointer<vtkFitImplicitFunction> fit =
    vtkSmartPointer<vtkFitImplicitFunction>::New();
  fit->SetInputConnection(points->GetOutputPort());
  fit->SetImplicitFunction(sphere);
  fit->SetThreshold(.01);
  fit->Update();
  std::cout << fit->GetOutput()->GetNumberOfPoints() << " out of "
            << points->GetNumberOfPoints() << " points are within "
            << fit->GetThreshold() << " of the implicit function" << std::endl;

  vtkSmartPointer<vtkSphereSource> sphereSource =
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->SetRadius(radius * .05);

  vtkSmartPointer<vtkGlyph3D> glyph3D =
    vtkSmartPointer<vtkGlyph3D>::New();
  glyph3D->SetInputConnection(fit->GetOutputPort());
  glyph3D->SetSourceConnection(sphereSource->GetOutputPort());
  glyph3D->ScalingOff();
  glyph3D->Update();

  vtkSmartPointer<vtkPolyDataMapper> glyph3DMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  glyph3DMapper->SetInputConnection(glyph3D->GetOutputPort());

  vtkSmartPointer<vtkActor> glyph3DActor =
    vtkSmartPointer<vtkActor>::New();
  glyph3DActor->SetMapper(glyph3DMapper);
  glyph3DActor->GetProperty()->SetColor(0.8900, 0.8100, 0.3400);

  // 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(glyph3DActor);

  // Generate an interesting view
  //
  ren1->ResetCamera();
  ren1->GetActiveCamera()->Azimuth(120);
  ren1->GetActiveCamera()->Elevation(30);
  ren1->GetActiveCamera()->Dolly(1.0);
  ren1->ResetCameraClippingRange();

  renWin->Render();
  iren->Initialize();
  iren->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(FitImplicitFunction)

find_package(VTK COMPONENTS 
  vtkvtkCommonCore
  vtkvtkCommonDataModel
  vtkvtkFiltersCore
  vtkvtkFiltersPoints
  vtkvtkFiltersSources
  vtkvtkInteractionStyle
  vtkvtkRenderingContextOpenGL2
  vtkvtkRenderingCore
  vtkvtkRenderingFreeType
  vtkvtkRenderingGL2PSOpenGL2
  vtkvtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping FitImplicitFunction: ${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(FitImplicitFunction MACOSX_BUNDLE FitImplicitFunction.cxx )
  target_link_libraries(FitImplicitFunction PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(FitImplicitFunction MACOSX_BUNDLE FitImplicitFunction.cxx )
  target_link_libraries(FitImplicitFunction PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS FitImplicitFunction
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build FitImplicitFunction

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

cd FitImplicitFunction/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:

./FitImplicitFunction

WINDOWS USERS

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