# EllipticalCylinder

VTKExamples/Cxx/GeometricObjects/EllipticalCylinder

### Description¶

The example creates an elliptical cross-section and stores it in a vtkPolyData. Then, the vtkLinearExtrusionFilter creates an elliptical cylinder by extruding the vtkPolyLine along a vector. The example sets the backface property of the vtkActor to show the front and back face of the cylinder.

EllipticalCylinderDemo to see the vtkPolyLine and the vector represented as an oriented arrow.

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¶

EllipticalCylinder.cxx

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkLinearExtrusionFilter.h>
#include <vtkNamedColors.h>
#include <vtkPoints.h>
#include <vtkPolyDataMapper.h>
#include <vtkPolyLine.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSmartPointer.h>

int main(int /* argc */, char * /* argv */ [])
{

double angle = 0;
double r1, r2;
double centerX, centerY;
r1 = 50;
r2 = 30;
centerX = 10.0;
centerY = 5.0;

vtkSmartPointer<vtkPoints> points =
vtkSmartPointer<vtkPoints>::New();
int id = 0;
while (angle <= 2.0 * vtkMath::Pi() + (vtkMath::Pi() / 60.0))
{
points->InsertNextPoint(r1 * cos(angle) + centerX,
r2 * sin(angle) + centerY,
0.0);
angle = angle + (vtkMath::Pi() / 60.0);
++id;
}

vtkSmartPointer<vtkPolyLine> line =
vtkSmartPointer<vtkPolyLine>::New();
line->GetPointIds()->SetNumberOfIds(id);
for(unsigned int i = 0; i < static_cast<unsigned int>(id); ++i)
{
line->GetPointIds()->SetId(i,i);
}

vtkSmartPointer<vtkCellArray> lines =
vtkSmartPointer<vtkCellArray>::New();
lines->InsertNextCell(line);

vtkSmartPointer<vtkPolyData> polyData =
vtkSmartPointer<vtkPolyData>::New();
polyData->SetPoints(points);
polyData->SetLines(lines);

vtkSmartPointer<vtkLinearExtrusionFilter> extrude =
vtkSmartPointer<vtkLinearExtrusionFilter>::New();
extrude->SetInputData(polyData);
extrude->SetExtrusionTypeToNormalExtrusion();
extrude->SetVector(0, 0, 100.0);
extrude->Update();

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

vtkSmartPointer<vtkPolyDataMapper> lineMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
lineMapper->SetInputData(polyData);

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

vtkSmartPointer<vtkPolyDataMapper> mapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
mapper->SetInputConnection(extrude->GetOutputPort());

vtkSmartPointer<vtkProperty> back =
vtkSmartPointer<vtkProperty>::New();
back->SetColor(colors->GetColor3d("Tomato").GetData());

vtkSmartPointer<vtkActor> actor =
vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
actor->GetProperty()->SetColor(colors->GetColor3d("Banana").GetData());
actor->SetBackfaceProperty(back);

vtkSmartPointer<vtkRenderer> ren =
vtkSmartPointer<vtkRenderer>::New();
ren->SetBackground(colors->GetColor3d("SlateGray").GetData());

vtkSmartPointer<vtkRenderWindow> renWin =
vtkSmartPointer<vtkRenderWindow>::New();
renWin->SetWindowName("Elliptical Cylinder");
renWin->SetSize(600, 600);

vtkSmartPointer<vtkRenderWindowInteractor> iren =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
iren->SetRenderWindow(renWin);

vtkSmartPointer<vtkInteractorStyleTrackballCamera> style =
vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New();
iren->SetInteractorStyle(style);

vtkSmartPointer<vtkCamera> camera =
vtkSmartPointer<vtkCamera>::New();
camera->SetPosition (0, 1, 0);
camera->SetFocalPoint (0, 0, 0);
camera->SetViewUp (0, 0, 1);
camera->Azimuth(30);
camera->Elevation(30);

ren->SetActiveCamera(camera);
ren->ResetCamera();
ren->ResetCameraClippingRange();

renWin->Render();
iren->Start();

return EXIT_SUCCESS;
}


### CMakeLists.txt¶

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(EllipticalCylinder)

find_package(VTK COMPONENTS
vtkCommonColor
vtkCommonCore
vtkCommonDataModel
vtkFiltersModeling
vtkInteractionStyle
vtkRenderingCore
vtkRenderingFreeType
vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
message("Skipping EllipticalCylinder: ${VTK_NOT_FOUND_MESSAGE}") return () endif() message (STATUS "VTK_VERSION:${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
# old system
include(${VTK_USE_FILE}) add_executable(EllipticalCylinder MACOSX_BUNDLE EllipticalCylinder.cxx ) target_link_libraries(EllipticalCylinder PRIVATE${VTK_LIBRARIES})
else ()
# include all components
add_executable(EllipticalCylinder MACOSX_BUNDLE EllipticalCylinder.cxx )
target_link_libraries(EllipticalCylinder PRIVATE ${VTK_LIBRARIES}) # vtk_module_autoinit is needed vtk_module_autoinit( TARGETS EllipticalCylinder MODULES${VTK_LIBRARIES}
)
endif ()


cd EllipticalCylinder/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:

./EllipticalCylinder


WINDOWS USERS

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