# QuadraticSurface

VTKExamples/Cxx/Visualization/QuadraticSurface

### Description

This example demonstrates how to create and display a quadratic surface.

### Code

QuadraticSurface.cxx

    #include <vtkSmartPointer.h>
    #include <vtkQuadric.h>
    #include <vtkSampleFunction.h>
    #include <vtkContourFilter.h>
    #include <vtkActor.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkPolyDataMapper.h>

    int main(int, char *[])
    {
      // Create the quadric function definition
      vtkSmartPointer<vtkQuadric> quadric =
        vtkSmartPointer<vtkQuadric>::New();
      quadric->SetCoefficients(.5,1,.2,0,.1,0,0,.2,0,0);

      // Sample the quadric function
      vtkSmartPointer<vtkSampleFunction> sample =
        vtkSmartPointer<vtkSampleFunction>::New();
      sample->SetSampleDimensions(50,50,50);
      sample->SetImplicitFunction(quadric);
      double xmin = 0, xmax=1, ymin=0, ymax=1, zmin=0, zmax=1;
      sample->SetModelBounds(xmin, xmax, ymin, ymax, zmin, zmax);

      vtkSmartPointer<vtkContourFilter> contourFilter =
        vtkSmartPointer<vtkContourFilter>::New();
      contourFilter->SetInputConnection(sample->GetOutputPort());
      contourFilter->GenerateValues(1, 1.0, 1.0);
      contourFilter->Update();

      // Visualize
      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(contourFilter->GetOutputPort());

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

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

      renderer->AddActor(actor);
      renderer->SetBackground(.3, .6, .3); // Background color green

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

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(QuadraticSurface)

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

    add_executable(QuadraticSurface MACOSX_BUNDLE QuadraticSurface.cxx )

    target_link_libraries(QuadraticSurface ${VTK_LIBRARIES})

### Download and Build QuadraticSurface

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

    cd QuadraticSurface/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:

    ./QuadraticSurface

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.