ENH: Add AmbientSpheres example.

Add the AmbientSpheres.cxx example from the VTK source tree to the VTK
wiki examples repository.

Author: Jon Haitz Legarreta Gorroño

Cxx/Rendering/AmbientSpheres.cxx

@@ -0,0 +1,148 @@
+#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(0.125);
+  sphere1->GetProperty()->SetDiffuse(0.0);
+  sphere1->GetProperty()->SetSpecular(0.0);
+
+  vtkSmartPointer<vtkActor> sphere2 = vtkSmartPointer<vtkActor>::New();
+  sphere2->SetMapper(sphereMapper);
+  sphere2->GetProperty()->SetColor(1,0,0);
+  sphere2->GetProperty()->SetAmbient(0.25);
+  sphere2->GetProperty()->SetDiffuse(0.0);
+  sphere2->GetProperty()->SetSpecular(0.0);
+  sphere2->AddPosition(1.25,0,0);
+
+  vtkSmartPointer<vtkActor> sphere3 = vtkSmartPointer<vtkActor>::New();
+  sphere3->SetMapper(sphereMapper);
+  sphere3->GetProperty()->SetColor(1,0,0);
+  sphere3->GetProperty()->SetAmbient(0.375);
+  sphere3->GetProperty()->SetDiffuse(0.0);
+  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(0.5);
+  sphere4->GetProperty()->SetDiffuse(0.0);
+  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(0.625);
+  sphere5->GetProperty()->SetDiffuse(0.0);
+  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(0.75);
+  sphere6->GetProperty()->SetDiffuse(0.0);
+  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(0.875);
+  sphere7->GetProperty()->SetDiffuse(0.0);
+  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(1.0);
+  sphere8->GetProperty()->SetDiffuse(0.0);
+  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(400, 200);
+
+  // 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;
+}
+
+
+
+