PlatonicSolids

VTKEx/Cxx/GeometricObjects/PlatonicSolids

Description¶

Display all five Platonic solids in a grid.

Platonic solids are regular, convex polyhedrons. They are constructed by congruent (identical in shape and size) regular (all angles equal and all sides equal) polygonal faces with the same number of faces meeting at each vertex.

Five solids satisfy the above criteria:

Figure	Tetrahedron	Cube	Octahedron	Icosahedron	Dodecahedron
Vertices	4	8	6 (2 × 3)	12 (4 × 3)	20 (8 + 4 × 3)
Edges	6	12	12	30	30
Faces	4	6	8	20	12

The relationship between vertices, edges and faces is given by Euler's formula:

V - E + F = 2

Other languages

See (Python)

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¶

PlatonicSolids.cxx

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkLookupTable.h>
#include <vtkNamedColors.h>
#include <vtkPlatonicSolidSource.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkTextActor.h>
#include <vtkTextMapper.h>
#include <vtkTextProperty.h>

#include <string>
#include <vector>

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

  // Each face has a different cell scalar
  // Here we create a lookup table with a different colour
  // for each face. The colors have been carefully
  // chosen so that adjacent cells are colored distinctly.
  vtkSmartPointer<vtkLookupTable> lut =
    vtkSmartPointer<vtkLookupTable>::New();
  lut->SetNumberOfTableValues(20);
  lut->SetTableRange(0.0, 19.0);
  lut->Build();
  lut->SetTableValue(0, 0.1, 0.1, 0.1);
  lut->SetTableValue(1, 0, 0, 1);
  lut->SetTableValue(2, 0, 1, 0);
  lut->SetTableValue(3, 0, 1, 1);
  lut->SetTableValue(4, 1, 0, 0);
  lut->SetTableValue(5, 1, 0, 1);
  lut->SetTableValue(6, 1, 1, 0);
  lut->SetTableValue(7, 0.9, 0.7, 0.9);
  lut->SetTableValue(8, 0.5, 0.5, 0.5);
  lut->SetTableValue(9, 0.0, 0.0, 0.7);
  lut->SetTableValue(10, 0.5, 0.7, 0.5);
  lut->SetTableValue(11, 0, 0.7, 0.7);
  lut->SetTableValue(12, 0.7, 0, 0);
  lut->SetTableValue(13, 0.7, 0, 0.7);
  lut->SetTableValue(14, 0.7, 0.7, 0);
  lut->SetTableValue(15, 0, 0, 0.4);
  lut->SetTableValue(16, 0, 0.4, 0);
  lut->SetTableValue(17, 0, 0.4, 0.4);
  lut->SetTableValue(18, 0.4, 0, 0);
  lut->SetTableValue(19, 0.4, 0, 0.4);

  std::vector<vtkSmartPointer<vtkPolyDataMapper>> mappers;
  std::vector<vtkSmartPointer<vtkActor>> actors;
  std::vector<vtkSmartPointer<vtkTextMapper>> textMappers;
  std::vector<vtkSmartPointer<vtkActor2D>> textActors;
  std::vector<vtkSmartPointer<vtkRenderer>> renderers;

  // Create a common text property.
  vtkSmartPointer<vtkTextProperty> textProperty =
    vtkSmartPointer<vtkTextProperty>::New();
  textProperty->SetFontSize(16);
  textProperty->SetJustificationToCentered();

  // Create the render window and interactor.
  vtkSmartPointer<vtkRenderWindow> renWin =
    vtkSmartPointer<vtkRenderWindow>::New();
  renWin->SetWindowName("Platonic Solids");
  vtkSmartPointer<vtkRenderWindowInteractor> iRen =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  iRen->SetRenderWindow(renWin);

  // There are five platonic solids.
  std::vector<std::string> names{"Tetrahedron", "Cube", "Octahedron",
                                 "Icosahedron", "Dodecahedron"};
  std::vector<vtkSmartPointer<vtkPlatonicSolidSource>> PlatonicSolids;
  for (auto i = 0; i < names.size(); ++i)
  {
    PlatonicSolids.push_back(vtkSmartPointer<vtkPlatonicSolidSource>::New());
    PlatonicSolids[i]->SetSolidType(i);

    mappers.push_back(vtkSmartPointer<vtkPolyDataMapper>::New());
    mappers[i]->SetInputConnection(PlatonicSolids[i]->GetOutputPort());
    mappers[i]->SetLookupTable(lut);
    mappers[i]->SetScalarRange(0, 19);

    actors.push_back(vtkSmartPointer<vtkActor>::New());
    actors[i]->SetMapper(mappers[i]);

    textMappers.push_back(vtkSmartPointer<vtkTextMapper>::New());
    textMappers[i]->SetInput(names[i].c_str());
    textMappers[i]->SetTextProperty(textProperty);

    textActors.push_back(vtkSmartPointer<vtkActor2D>::New());
    textActors[i]->SetMapper(textMappers[i]);
    textActors[i]->SetPosition(120, 16);

    renderers.push_back(vtkSmartPointer<vtkRenderer>::New());
    renderers[i]->AddActor(actors[i]);
    renderers[i]->AddViewProp(textActors[i]);

    renWin->AddRenderer(renderers[i]);
  }

  // Setup the viewports
  auto xGridDimensions = 3;
  auto yGridDimensions = 2;
  auto rendererSize = 300;
  renWin->SetSize(rendererSize * xGridDimensions,
                  rendererSize * yGridDimensions);
  for (auto row = 0; row < yGridDimensions; ++row)
  {
    for (auto col = 0; col < xGridDimensions; ++col)
    {
      auto index = row * xGridDimensions + col;

      // (xmin, ymin, xmax, ymax)
      double viewport[4] = {
        static_cast<double>(col) / xGridDimensions,
        static_cast<double>(yGridDimensions - (row + 1)) / yGridDimensions,
        static_cast<double>(col + 1) / xGridDimensions,
        static_cast<double>(yGridDimensions - row) / yGridDimensions};
      if (index > (actors.size() - 1))
      {
        // Add a renderer even if there is no actor.
        // This makes the render window background all the same color.
        vtkSmartPointer<vtkRenderer> ren = vtkSmartPointer<vtkRenderer>::New();
        ren->SetBackground(colors->GetColor3d("SlateGray").GetData());
        ren->SetViewport(viewport);
        renWin->AddRenderer(ren);
        continue;
      }

      renderers[index]->SetViewport(viewport);
      renderers[index]->SetBackground(
        colors->GetColor3d("SlateGray").GetData());
      renderers[index]->ResetCamera();
      renderers[index]->GetActiveCamera()->Azimuth(4.5);
      renderers[index]->GetActiveCamera()->Elevation(-18);
      renderers[index]->ResetCameraClippingRange();
    }
  }

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

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(PlatonicSolids)

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

Download and Build PlatonicSolids¶

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

cd PlatonicSolids/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:

./PlatonicSolids

WINDOWS USERS

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