ConvexPointSet

VTKExamples/Cxx/GeometricObjects/ConvexPointSet


Description

vtkConvexPointSet object represents a 3D cell defined by a convex set of points. An example of such a cell is an octant (from an octree). vtkConvexPointSet uses the ordered triangulations approach vtkOrderedTriangulator) to create triangulations guaranteed to be compatible across shared faces.

Other Languages

See (Python), (Java)

Question

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

Code

ConvexPointSet.cxx

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkConvexPointSet.h>
#include <vtkDataSetMapper.h>
#include <vtkGlyph3DMapper.h>
#include <vtkNamedColors.h>
#include <vtkPoints.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkShrinkFilter.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkUnstructuredGrid.h>

int main (int, char *[])
{
  vtkSmartPointer<vtkConvexPointSet> cps =
    vtkSmartPointer<vtkConvexPointSet>::New();
  vtkSmartPointer<vtkPoints> points =
    vtkSmartPointer<vtkPoints>::New();
  points->InsertNextPoint( 0, 0, 0);
  points->InsertNextPoint( 1, 0, 0);
  points->InsertNextPoint( 1, 1, 0);
  points->InsertNextPoint( 0, 1, 0);
  points->InsertNextPoint( 0, 0, 1);
  points->InsertNextPoint( 1, 0, 1);
  points->InsertNextPoint( 1, 1, 1);
  points->InsertNextPoint( 0, 1, 1);
  points->InsertNextPoint( 0.5, 0, 0);
  points->InsertNextPoint( 1, 0.5, 0);
  points->InsertNextPoint( 0.5, 1, 0);
  points->InsertNextPoint( 0, 0.5, 0);
  points->InsertNextPoint( 0.5, 0.5, 0);

  for (int i = 0; i < 13; ++i)
  {
    cps->GetPointIds()->InsertId(i,i);
  }

  vtkSmartPointer<vtkUnstructuredGrid> ug =
    vtkSmartPointer<vtkUnstructuredGrid>::New();
  ug->Allocate(1,1);
  ug->InsertNextCell(cps->GetCellType(), cps->GetPointIds());
  ug->SetPoints(points);

  vtkSmartPointer<vtkNamedColors> colors =
    vtkSmartPointer<vtkNamedColors>::New();

  vtkSmartPointer<vtkDataSetMapper> mapper =
    vtkSmartPointer<vtkDataSetMapper>::New();
  mapper->SetInputData(ug);

  vtkSmartPointer<vtkActor> actor =
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);
  actor->GetProperty()->SetColor(colors->GetColor3d("Tomato").GetData());
  actor->GetProperty()->SetLineWidth(3);
  actor->GetProperty()->EdgeVisibilityOn();

  // Glyph the points
  vtkSmartPointer<vtkSphereSource> sphere =
    vtkSmartPointer<vtkSphereSource>::New();
  sphere->SetPhiResolution(21);
  sphere->SetThetaResolution(21);
  sphere->SetRadius(.03);

  // Create a polydata to store everything in
  vtkSmartPointer<vtkPolyData> polyData =
    vtkSmartPointer<vtkPolyData>::New();
  polyData->SetPoints(points);

  vtkSmartPointer<vtkGlyph3DMapper> pointMapper =
    vtkSmartPointer<vtkGlyph3DMapper>::New();
  pointMapper->SetInputData(polyData);
  pointMapper->SetSourceConnection(sphere->GetOutputPort());

  vtkSmartPointer<vtkActor> pointActor =
    vtkSmartPointer<vtkActor>::New();
  pointActor->SetMapper(pointMapper);
  pointActor->GetProperty()->SetColor(colors->GetColor3d("Peacock").GetData());

  //Create a renderer, render window, and interactor
  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->SetWindowName("Convex Point Set");
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);

  //Add the actors to the scene
  renderer->AddActor(actor);
  renderer->AddActor(pointActor);
  renderer->SetBackground(colors->GetColor3d("Silver").GetData());

  renderer->ResetCamera();
  renderer->GetActiveCamera()->Azimuth(210);
  renderer->GetActiveCamera()->Elevation(30);
  renderer->ResetCameraClippingRange();

  //Render and interact
  renderWindow->SetSize(640, 480);  
  renderWindow->Render();
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(ConvexPointSet)

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

Download and Build ConvexPointSet

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

cd ConvexPointSet/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:

./ConvexPointSet

WINDOWS USERS

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