Cube

VTKExamples/Cxx/GeometricObjects/Cube


Description

This is based on the C++ example Examples/DataManipulation/Cxx/Cube.cxx in the VTK source distribution.

It illustrates the manual use of vtkPolyData to construct a cube and differs from the Wiki examples Cube1.cxx and Cube1.py, which use vtkCubeSource.

Other Languages

See (Python), (CSharp)

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

Cube.cxx

/*=========================================================================

  Program:   Visualization Toolkit
  Module:    Cube.cxx

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
// This example shows how to manually create vtkPolyData.

// For a python version, please see:
// [Cube](https://lorensen.github.io/VTKExamples/site/Python/GeometricObjects/Cube/)

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkCellArray.h>
#include <vtkFloatArray.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPointData.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

#include <array>

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

  std::array<std::array<double, 3>, 8> pts = {{{{0, 0, 0}},
                                               {{1, 0, 0}},
                                               {{1, 1, 0}},
                                               {{0, 1, 0}},
                                               {{0, 0, 1}},
                                               {{1, 0, 1}},
                                               {{1, 1, 1}},
                                               {{0, 1, 1}}}};
  // The ordering of the corner points on each face.
  std::array<std::array<vtkIdType, 4>, 6> ordering = {{{{0, 1, 2, 3}},
                                                       {{4, 5, 6, 7}},
                                                       {{0, 1, 5, 4}},
                                                       {{1, 2, 6, 5}},
                                                       {{2, 3, 7, 6}},
                                                       {{3, 0, 4, 7}}}};

  // We'll create the building blocks of polydata including data attributes.
  vtkNew<vtkPolyData> cube;
  vtkNew<vtkPoints> points;
  vtkNew<vtkCellArray> polys;
  vtkNew<vtkFloatArray> scalars;

  // Load the point, cell, and data attributes.
  for (auto i = 0ul; i < pts.size(); ++i)
  {
    points->InsertPoint(i, pts[i].data());
    scalars->InsertTuple1(i, i);
  }
  for (auto&& i : ordering)
  {
    polys->InsertNextCell(vtkIdType(i.size()), i.data());
  }

  // We now assign the pieces to the vtkPolyData.
  cube->SetPoints(points);
  cube->SetPolys(polys);
  cube->GetPointData()->SetScalars(scalars);

  // Now we'll look at it.
  vtkNew<vtkPolyDataMapper> cubeMapper;
  cubeMapper->SetInputData(cube);
  cubeMapper->SetScalarRange(cube->GetScalarRange());
  vtkNew<vtkActor> cubeActor;
  cubeActor->SetMapper(cubeMapper);

  // The usual rendering stuff.
  vtkNew<vtkCamera> camera;
  camera->SetPosition(1, 1, 1);
  camera->SetFocalPoint(0, 0, 0);

  vtkNew<vtkRenderer> renderer;
  vtkNew<vtkRenderWindow> renWin;
  renWin->AddRenderer(renderer);

  vtkNew<vtkRenderWindowInteractor> iren;
  iren->SetRenderWindow(renWin);

  renderer->AddActor(cubeActor);
  renderer->SetActiveCamera(camera);
  renderer->ResetCamera();
  renderer->SetBackground(colors->GetColor3d("Cornsilk").GetData());

  renWin->SetSize(600, 600);

  // interact with data
  renWin->Render();
  iren->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(Cube)

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

Download and Build Cube

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

cd Cube/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:

./Cube

WINDOWS USERS

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