ENH: Added SimpleRayCast example from VTK Book.

Former-commit-id: 49ad3a92

src/Cxx/Medical/MedicalDemo4.cxx

@@ -121,19 +121,16 @@ int main (int argc, char *argv[])
   camera->SetViewUp (0, 0, -1);
   camera->SetPosition (c[0], c[1] - 400, c[2]);
   camera->SetFocalPoint (c[0], c[1], c[2]);
-  camera->ComputeViewPlaneNormal();
   camera->Azimuth(30.0);
   camera->Elevation(30.0);
 
   // Set a background color for the renderer
   ren->SetBackground(.2, .3, .4);
 
-  renWin->SetSize(640, 480);
   // Increase the size of the render window
   renWin->SetSize(640, 480);
 
   // Interact with the data.
-  iren->Initialize();
   iren->Start();
 
   return EXIT_SUCCESS;

src/Cxx/VolumeRendering/CMakeLists.txt

 project (${WIKI}VolumeRendering)
 
 if(NOT WikiExamples_BINARY_DIR)
-find_package(VTK REQUIRED)
-if(NOT VTK_USE_RENDERING)
-  message(FATAL_ERROR "Example ${PROJECT_NAME} requires VTK_USE_RENDERING.")
-endif()
-include(${VTK_USE_FILE})
+  find_package(VTK REQUIRED)
+  include(${VTK_USE_FILE})
 endif()
 
-if("${VTK_MAJOR_VERSION}.${VTK_MINOR_VERSION}" LESS 5.8)
-  set(KIT_LIBS vtkRendering vtkVolumeRendering vtkHybrid)
-else()
-  set(KIT_LIBS ${VTK_LIBRARIES})
-endif()
+set(KIT_LIBS ${VTK_LIBRARIES})
+
 #
 # Build all .cxx files in the directory
 file(GLOB ALL_FILES *.cxx)
@@ -40,6 +34,7 @@ if (VTK_RENDERING_BACKEND STREQUAL "OpenGL2")
     MinIntensityRendering
     IntermixedUnstructuredGrid
     FixedPointVolumeRayCastMapperCT
+    SimpleRayCast
   )
 else()
   set(NEEDS_ARGS
@@ -65,6 +60,9 @@ add_test(${KIT}-MinIntensityRendering ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${KIT}Cx
   TestMinIntensityRendering ${DATA}/ironProt.vtk)
 endif()
 
+add_test(${KIT}-SimpleRayCast ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${KIT}CxxTests
+  TestSimpleRayCast ${DATA}/ironProt.vtk)
+
 add_test(${KIT}-PseudoVolumeRendering ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${KIT}CxxTests
   TestPseudoVolumeRendering ${DATA}/combxyz.bin ${DATA}/combq.bin)
 

src/Cxx/VolumeRendering/SimpleRayCast.cxx

+#include <vtkSmartPointer.h>
+#include <vtkVolume.h>
+#include <vtkFixedPointVolumeRayCastMapper.h>
+#include <vtkVolumeProperty.h>
+#include <vtkColorTransferFunction.h>
+#include <vtkPiecewiseFunction.h>
+#include <vtkStructuredPointsReader.h>
+#include <vtkRenderWindowInteractor.h>
+#include <vtkRenderWindow.h>
+#include <vtkRenderer.h>
+#include <vtkCamera.h>
+#include <vtkNamedColors.h>
+
+int main (int argc, char *argv[])
+{
+  if (argc < 2)
+  {
+    std::cout << "Usage: " << argv[0] << " ironProt.vtk" << std::endl;
+    return EXIT_FAILURE;
+  }
+
+// This is a simple volume rendering example that
+// uses a vtkFixedPointVolumeRayCastMapper
+
+// Create the standard renderer, render window
+// and interactor
+  vtkSmartPointer<vtkNamedColors> colors =
+    vtkSmartPointer<vtkNamedColors>::New();
+
+  vtkSmartPointer<vtkRenderer> ren1 =
+    vtkSmartPointer<vtkRenderer>::New();
+
+  vtkSmartPointer<vtkRenderWindow> renWin =
+    vtkSmartPointer<vtkRenderWindow>::New();
+  renWin->AddRenderer(ren1);
+
+  vtkSmartPointer<vtkRenderWindowInteractor> iren =
+    vtkSmartPointer<vtkRenderWindowInteractor>::New();
+  iren->SetRenderWindow(renWin);
+
+// Create the reader for the data
+  vtkSmartPointer<vtkStructuredPointsReader> reader =
+    vtkSmartPointer<vtkStructuredPointsReader>::New();
+  reader->SetFileName(argv[1]);
+
+// Create transfer mapping scalar value to opacity
+  vtkSmartPointer<vtkPiecewiseFunction> opacityTransferFunction =
+    vtkSmartPointer<vtkPiecewiseFunction>::New();
+  opacityTransferFunction->AddPoint(20, 0.0);
+  opacityTransferFunction->AddPoint(255, 0.2);
+
+// Create transfer mapping scalar value to color
+  vtkSmartPointer<vtkColorTransferFunction> colorTransferFunction =
+    vtkSmartPointer<vtkColorTransferFunction>::New();
+  colorTransferFunction->AddRGBPoint(0.0, 0.0, 0.0, 0.0);
+  colorTransferFunction->AddRGBPoint(64.0, 1.0, 0.0, 0.0);
+  colorTransferFunction->AddRGBPoint(128.0, 0.0, 0.0, 1.0);
+  colorTransferFunction->AddRGBPoint(192.0, 0.0, 1.0, 0.0);
+  colorTransferFunction->AddRGBPoint(255.0, 0.0, 0.2, 0.0);
+
+// The property describes how the data will look
+  vtkSmartPointer<vtkVolumeProperty> volumeProperty =
+    vtkSmartPointer<vtkVolumeProperty>::New();
+  volumeProperty->SetColor(colorTransferFunction);
+  volumeProperty->SetScalarOpacity(opacityTransferFunction);
+  volumeProperty->ShadeOn();
+  volumeProperty->SetInterpolationTypeToLinear();
+
+// The mapper / ray cast function know how to render the data
+  vtkSmartPointer<vtkFixedPointVolumeRayCastMapper> volumeMapper =
+    vtkSmartPointer<vtkFixedPointVolumeRayCastMapper>::New();
+  volumeMapper->SetInputConnection(reader->GetOutputPort());
+  
+// The volume holds the mapper and the property and
+// can be used to position/orient the volume
+  vtkSmartPointer<vtkVolume> volume =
+    vtkSmartPointer<vtkVolume>::New();
+  volume->SetMapper(volumeMapper);
+  volume->SetProperty(volumeProperty);
+
+  ren1->AddVolume(volume);
+  ren1->SetBackground(colors->GetColor3d("Wheat").GetData());
+  ren1->GetActiveCamera()->Azimuth(45);
+  ren1->GetActiveCamera()->Elevation(30);
+  ren1->ResetCameraClippingRange();
+  ren1->ResetCamera();
+
+  renWin->SetSize(600, 600);
+  renWin->Render();
+
+  iren->Start();
+
+  return EXIT_SUCCESS;
+}