# VTK/Examples/Cxx/GeometricObjects/Hexahedron

< VTK‎ | Examples‎ | Cxx

This example creates eight points and creates a hexahedron from the points.

## Hexahedron.cxx

```#include <vtkVersion.h>
#include <vtkCellArray.h>
#include <vtkPoints.h>
#include <vtkHexahedron.h>
#include <vtkUnstructuredGrid.h>

#include <vtkSmartPointer.h>
#include <vtkDataSetMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>

int main(int, char *[])
{
// Setup the coordinates of eight points
// (the two faces must be in counter clockwise order as viewd from the outside)
double P0[3] = {0.0, 0.0, 0.0};
double P1[3] = {1.0, 0.0, 0.0};
double P2[3] = {1.0, 1.0, 0.0};
double P3[3] = {0.0, 1.0, 0.0};
double P4[3] = {0.0, 0.0, 1.0};
double P5[3] = {1.0, 0.0, 1.0};
double P6[3] = {1.0, 1.0, 1.0};
double P7[3] = {0.0, 1.0, 1.0};

// Create the points
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
points->InsertNextPoint(P0);
points->InsertNextPoint(P1);
points->InsertNextPoint(P2);
points->InsertNextPoint(P3);
points->InsertNextPoint(P4);
points->InsertNextPoint(P5);
points->InsertNextPoint(P6);
points->InsertNextPoint(P7);

// Create a hexahedron from the points
vtkSmartPointer<vtkHexahedron> hex =
vtkSmartPointer<vtkHexahedron>::New();
hex->GetPointIds()->SetId(0,0);
hex->GetPointIds()->SetId(1,1);
hex->GetPointIds()->SetId(2,2);
hex->GetPointIds()->SetId(3,3);
hex->GetPointIds()->SetId(4,4);
hex->GetPointIds()->SetId(5,5);
hex->GetPointIds()->SetId(6,6);
hex->GetPointIds()->SetId(7,7);

// Add the hexahedron to a cell array
vtkSmartPointer<vtkCellArray> hexs =
vtkSmartPointer<vtkCellArray>::New();
hexs->InsertNextCell(hex);

// Add the points and hexahedron to an unstructured grid
vtkSmartPointer<vtkUnstructuredGrid> uGrid =
vtkSmartPointer<vtkUnstructuredGrid>::New();
uGrid->SetPoints(points);
uGrid->InsertNextCell(hex->GetCellType(), hex->GetPointIds());

// Visualize
vtkSmartPointer<vtkDataSetMapper> mapper =
vtkSmartPointer<vtkDataSetMapper>::New();
#if VTK_MAJOR_VERSION <= 5
mapper->SetInputConnection(uGrid->GetProducerPort());
#else
mapper->SetInputData(uGrid);
#endif

vtkSmartPointer<vtkActor> actor =
vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);

vtkSmartPointer<vtkRenderer> renderer =
vtkSmartPointer<vtkRenderer>::New();
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
renderWindowInteractor->SetRenderWindow(renderWindow);

renderer->SetBackground(.2, .3, .4);

renderWindow->Render();
renderWindowInteractor->Start();

return EXIT_SUCCESS;
}
```

# Please try the new VTKExamples website.

## CMakeLists.txt

```cmake_minimum_required(VERSION 2.8)

PROJECT(Hexahedron)

find_package(VTK REQUIRED)
include(\${VTK_USE_FILE})

if(VTK_LIBRARIES)
else()
endif()
```

```cd Hexahedron/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:

```./Hexahedron
```

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