# Cube

vtk-examples/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

### Code¶

Cube.cxx

#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, 3, 2, 1}},
{{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->SetWindowName("Cube");

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

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 3.12 FATAL_ERROR)

project(Cube)

find_package(VTK COMPONENTS
CommonColor
CommonCore
CommonDataModel
InteractionStyle
RenderingContextOpenGL2
RenderingCore
RenderingFreeType
RenderingGL2PSOpenGL2
RenderingOpenGL2
)

if (NOT VTK_FOUND)
message(FATAL_ERROR "Cube: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
target_link_libraries(Cube PRIVATE ${VTK_LIBRARIES} ) # vtk_module_autoinit is needed vtk_module_autoinit( TARGETS Cube MODULES${VTK_LIBRARIES}
)


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.