SimpleRayCast
VTKExamples/Cxx/VolumeRendering/SimpleRayCast
Description¶
Volume rendering of a high potential iron protein.
Info
See Figure 7-34 in Chapter 7 the VTK Textbook.
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¶
SimpleRayCast.cxx
#include <vtkCamera.h> #include <vtkColorTransferFunction.h> #include <vtkFixedPointVolumeRayCastMapper.h> #include <vtkNamedColors.h> #include <vtkPiecewiseFunction.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkRenderer.h> #include <vtkSmartPointer.h> #include <vtkStructuredPointsReader.h> #include <vtkVolume.h> #include <vtkVolumeProperty.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; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.3 FATAL_ERROR) project(SimpleRayCast) find_package(VTK COMPONENTS vtkCommonColor vtkCommonCore vtkCommonDataModel vtkIOLegacy vtkInteractionStyle vtkRenderingCore vtkRenderingFreeType vtkRenderingOpenGL2 vtkRenderingVolume vtkRenderingVolumeOpenGL2 QUIET) if (NOT VTK_FOUND) message("Skipping SimpleRayCast: ${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(SimpleRayCast MACOSX_BUNDLE SimpleRayCast.cxx ) target_link_libraries(SimpleRayCast PRIVATE ${VTK_LIBRARIES}) else () # include all components add_executable(SimpleRayCast MACOSX_BUNDLE SimpleRayCast.cxx ) target_link_libraries(SimpleRayCast PRIVATE ${VTK_LIBRARIES}) # vtk_module_autoinit is needed vtk_module_autoinit( TARGETS SimpleRayCast MODULES ${VTK_LIBRARIES} ) endif ()
Download and Build SimpleRayCast¶
Click here to download SimpleRayCast and its CMakeLists.txt file. Once the tarball SimpleRayCast.tar has been downloaded and extracted,
cd SimpleRayCast/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:
./SimpleRayCast
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.