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
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.