# DiffuseSpheres

VTKExamples/Cxx/Rendering/DiffuseSpheres

Note

This original source code for this example is here.

### Code

DiffuseSpheres.cxx

    #include <vtkSmartPointer.h>
    #include <vtkSphereSource.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkProperty.h>
    #include <vtkCamera.h>
    #include <vtkLight.h>

    int main(int, char *[])
    {
      // The following lines create a sphere represented by polygons.
      //
      vtkSmartPointer<vtkSphereSource> sphere = vtkSmartPointer<vtkSphereSource>::New();
      sphere->SetThetaResolution(100);
      sphere->SetPhiResolution(50);

      // The mapper is responsible for pushing the geometry into the graphics
      // library. It may also do color mapping, if scalars or other attributes
      // are defined.
      //
      vtkSmartPointer<vtkPolyDataMapper> sphereMapper = vtkSmartPointer<vtkPolyDataMapper>::New();
      sphereMapper->SetInputConnection(sphere->GetOutputPort());

      // The actor is a grouping mechanism: besides the geometry (mapper), it
      // also has a property, transformation matrix, and/or texture map.
      // In this example we create eight different spheres (two rows of four
      // spheres) and set the specular lighting coefficients. A little ambient
      // is turned on so the sphere is not completely black on the back side.
      //
      vtkSmartPointer<vtkActor> sphere1 = vtkSmartPointer<vtkActor>::New();
      sphere1->SetMapper(sphereMapper);
      sphere1->GetProperty()->SetColor(1,0,0);
      sphere1->GetProperty()->SetAmbient(0.3);
      sphere1->GetProperty()->SetDiffuse(0.0);
      sphere1->GetProperty()->SetSpecular(0.0);
      sphere1->GetProperty()->SetSpecularPower(5.0);

      vtkSmartPointer<vtkActor> sphere2 = vtkSmartPointer<vtkActor>::New();
      sphere2->SetMapper(sphereMapper);
      sphere2->GetProperty()->SetColor(1,0,0);
      sphere2->GetProperty()->SetAmbient(0.3);
      sphere2->GetProperty()->SetDiffuse(0.125);
      sphere2->GetProperty()->SetSpecular(0.0);
      sphere2->GetProperty()->SetSpecularPower(10.0);
      sphere2->AddPosition(1.25,0,0);

      vtkSmartPointer<vtkActor> sphere3 = vtkSmartPointer<vtkActor>::New();
      sphere3->SetMapper(sphereMapper);
      sphere3->GetProperty()->SetColor(1,0,0);
      sphere3->GetProperty()->SetAmbient(0.3);
      sphere3->GetProperty()->SetDiffuse(0.25);
      sphere3->GetProperty()->SetSpecular(0.0);
      sphere3->AddPosition(2.5,0,0);

      vtkSmartPointer<vtkActor> sphere4 = vtkSmartPointer<vtkActor>::New();
      sphere4->SetMapper(sphereMapper);
      sphere4->GetProperty()->SetColor(1,0,0);
      sphere4->GetProperty()->SetAmbient(0.3);
      sphere4->GetProperty()->SetDiffuse(0.375);
      sphere4->GetProperty()->SetSpecular(0.0);
      sphere4->AddPosition(3.75,0,0);

      vtkSmartPointer<vtkActor> sphere5 = vtkSmartPointer<vtkActor>::New();
      sphere5->SetMapper(sphereMapper);
      sphere5->GetProperty()->SetColor(1,0,0);
      sphere5->GetProperty()->SetAmbient(0.3);
      sphere5->GetProperty()->SetDiffuse(0.5);
      sphere5->GetProperty()->SetSpecular(0.0);
      sphere5->AddPosition(0.0,1.25,0);

      vtkSmartPointer<vtkActor> sphere6 = vtkSmartPointer<vtkActor>::New();
      sphere6->SetMapper(sphereMapper);
      sphere6->GetProperty()->SetColor(1,0,0);
      sphere6->GetProperty()->SetAmbient(0.3);
      sphere6->GetProperty()->SetDiffuse(0.625);
      sphere6->GetProperty()->SetSpecular(0.0);
      sphere6->AddPosition(1.25,1.25,0);

      vtkSmartPointer<vtkActor> sphere7 = vtkSmartPointer<vtkActor>::New();
      sphere7->SetMapper(sphereMapper);
      sphere7->GetProperty()->SetColor(1,0,0);
      sphere7->GetProperty()->SetAmbient(0.3);
      sphere7->GetProperty()->SetDiffuse(0.75);
      sphere7->GetProperty()->SetSpecular(0.0);
      sphere7->AddPosition(2.5,1.25,0);

      vtkSmartPointer<vtkActor> sphere8 = vtkSmartPointer<vtkActor>::New();
      sphere8->SetMapper(sphereMapper);
      sphere8->GetProperty()->SetColor(1,0,0);
      sphere8->GetProperty()->SetAmbient(0.3);
      sphere8->GetProperty()->SetDiffuse(0.875);
      sphere8->GetProperty()->SetSpecular(0.0);
      sphere8->AddPosition(3.75,1.25,0);

      // Create the graphics structure. The renderer renders into the
      // render window. The render window interactor captures mouse events
      // and will perform appropriate camera or actor manipulation
      // depending on the nature of the events.
      //
      vtkSmartPointer<vtkRenderer> ren1 = vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renWin = vtkSmartPointer<vtkRenderWindow>::New();
      renWin->AddRenderer(ren1);
      vtkSmartPointer<vtkRenderWindowInteractor> iren = vtkSmartPointer<vtkRenderWindowInteractor>::New();
      iren->SetRenderWindow(renWin);

      // Add the actors to the renderer, set the background and size.
      //
      ren1->AddActor(sphere1);
      ren1->AddActor(sphere2);
      ren1->AddActor(sphere3);
      ren1->AddActor(sphere4);
      ren1->AddActor(sphere5);
      ren1->AddActor(sphere6);
      ren1->AddActor(sphere7);
      ren1->AddActor(sphere8);
      ren1->SetBackground(0.1, 0.2, 0.4);
      renWin->SetSize(600, 400);

      // Set up the lighting.
      //
      vtkSmartPointer<vtkLight> light = vtkSmartPointer<vtkLight>::New();
      light->SetFocalPoint(1.875,0.6125,0);
      light->SetPosition(0.875,1.6125,1);
      ren1->AddLight(light);

      // We want to eliminate perspective effects on the apparent lighting.
      // Parallel camera projection will be used. To zoom in parallel projection
      // mode, the ParallelScale is set.
      //
      ren1->GetActiveCamera()->SetFocalPoint(0,0,0);
      ren1->GetActiveCamera()->SetPosition(0,0,1);
      ren1->GetActiveCamera()->SetViewUp(0,1,0);
      ren1->GetActiveCamera()->ParallelProjectionOn();
      ren1->ResetCamera();
      ren1->GetActiveCamera()->SetParallelScale(1.5);

      // This starts the event loop and invokes an initial render.
      //
      iren->Initialize();
      iren->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(DiffuseSpheres)

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

    add_executable(DiffuseSpheres MACOSX_BUNDLE DiffuseSpheres.cxx )

    target_link_libraries(DiffuseSpheres ${VTK_LIBRARIES})

### Download and Build DiffuseSpheres

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

    cd DiffuseSpheres/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:

    ./DiffuseSpheres

WINDOWS USERS

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