RenderLargeImage
VTKExamples/Cxx/Visualization/RenderLargeImage
Description¶
This example renders a high resolution image. The image can be much larger than the window on the screen. It is useful if you need an image for a large poster, or you can down sample the image to produce a high quality anti-aliased image.
The example takes up to three arguments. The first, an input polydata, is required, as is the second, a .png file to hold the high res image. An optional third argument specifies the magnification of the high res image (default 4).
Code¶
RenderLargeImage.cxx
#include <vtkSmartPointer.h> #include <vtkActor.h> #include <vtkCamera.h> #include <vtkImageViewer.h> #include <vtkPNGWriter.h> #include <vtkPolyDataMapper.h> #include <vtkRenderLargeImage.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkRenderer.h> #include <vtkXMLPolyDataReader.h> int main (int argc, char *argv[]) { if (argc < 3) { std::cerr << "Usage: " << argv[0] << " Input(.vtp) Output(.png) [Magnification]" << std::endl; return EXIT_FAILURE; } int magnification = 4; if (argc == 4) { magnification = atoi(argv[3]); } vtkSmartPointer<vtkXMLPolyDataReader> reader = vtkSmartPointer<vtkXMLPolyDataReader>::New(); reader->SetFileName(argv[1]); vtkSmartPointer< vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New(); mapper->SetInputConnection(reader->GetOutputPort()); vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New(); actor->SetMapper(mapper); vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New(); vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); vtkSmartPointer<vtkRenderWindowInteractor> interactor = vtkSmartPointer<vtkRenderWindowInteractor>::New(); interactor->SetRenderWindow(renderWindow); renderWindow->AddRenderer(renderer); renderer->AddActor(actor); // Let the renderer compute good position and focal point renderer->GetActiveCamera()->Azimuth(30); renderer->GetActiveCamera()->Elevation(30); renderer->ResetCamera(); renderer->GetActiveCamera()->Dolly(1.4); renderer->ResetCameraClippingRange(); renderer->SetBackground(.3, .4, .5); renderWindow->SetSize(640, 480); renderWindow->Render(); std::cout << "Interact with image to get desired view and then press 'e'" << std::endl; interactor->Start(); std::cout << "Generating large image size: " << renderWindow->GetSize()[0] * magnification << " by " << renderWindow->GetSize()[1] * magnification << std::endl; vtkSmartPointer<vtkRenderLargeImage> renderLarge = vtkSmartPointer<vtkRenderLargeImage>::New(); renderLarge->SetInput(renderer); renderLarge->SetMagnification(magnification); std::cout << "Saving image in " << argv[2] << std::endl; vtkSmartPointer<vtkPNGWriter> writer = vtkSmartPointer<vtkPNGWriter>::New(); writer->SetFileName(argv[2]); writer->SetInputConnection(renderLarge->GetOutputPort()); writer->Write(); return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(RenderLargeImage) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(RenderLargeImage MACOSX_BUNDLE RenderLargeImage.cxx) target_link_libraries(RenderLargeImage ${VTK_LIBRARIES})
Download and Build RenderLargeImage¶
Danger
The generation of tar files has not been ported to the new VTKExamples. Some tarballs may be missing or out-of-date.
Click here to download RenderLargeImage and its CMakeLists.txt file. Once the tarball RenderLargeImage.tar has been downloaded and extracted,
cd RenderLargeImage/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:
./RenderLargeImage
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.