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OpenVRVolume

vtk-examples/Cxx/VolumeRendering/OpenVRVolume

Description

This example renders a simple artificial 10x10x10 volume in OpenVR.

Note that for the interactions to work in VTK >= 9.1, you will have to copy the .json manifest files from the subfolder Rendering/OpenVR in VTK's source to the working directory in which the tests are run!

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

OpenVRVolume.cxx

#include <vtkActor.h>
#include <vtkColorSeries.h>
#include <vtkColorTransferFunction.h>
#include <vtkImageData.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkOpenVRRenderWindow.h>
#include <vtkOpenVRRenderWindowInteractor.h>
#include <vtkOpenVRRenderer.h>
#include <vtkPiecewiseFunction.h>
#include <vtkSmartVolumeMapper.h>
#include <vtkVolumeProperty.h>

int main(int argc, char* argv[])
{
  int dim[3] = {10, 10, 10};
  double spc[3] = {0.05, 0.05, 0.05};
  vtkNew<vtkImageData> img;
  img->SetDimensions(dim);
  img->AllocateScalars(VTK_INT, 1);
  img->SetSpacing(spc);
  for (int x = 0; x < dim[0]; ++x)
    for (int y = 0; y < dim[1]; ++y)
      for (int z = 0; z < dim[2]; ++z)
      {
        img->SetScalarComponentFromDouble(x, y, z, 0, x);
      }
  vtkNew<vtkColorSeries> colors;
  colors->SetColorScheme(vtkColorSeries::BREWER_QUALITATIVE_SET3);
  vtkNew<vtkColorTransferFunction> ctf;
  for (int x = 0; x < dim[0]; ++x)
  {
    auto c = colors->GetColor(x);
    ctf->AddRGBPoint(x, c.GetRed() / 255.0, c.GetGreen() / 255.0,
                     c.GetBlue() / 255.0);
  }
  ctf->AddRGBPoint(dim[0], 1.0, 1.0, 1.0);
  ctf->Build();
  vtkNew<vtkSmartVolumeMapper> volMapper;
  vtkNew<vtkVolume> volume;
  vtkNew<vtkVolumeProperty> volProp;
  volMapper->SetBlendModeToComposite();
  volume->SetMapper(volMapper);
  volume->SetProperty(volProp);
  volume->SetVisibility(true);
  volMapper->SetInputData(img);
  volProp->SetColor(0, ctf);
  vtkNew<vtkPiecewiseFunction> otf;
  otf->AddPoint(0.0, 1.0);
  otf->AddPoint(dim[0], 1.0);
  volProp->SetScalarOpacity(0, otf);
  volProp->Modified();
  volProp->SetScalarOpacityUnitDistance(1);

  vtkNew<vtkOpenVRRenderWindow> renderWindow;
  renderWindow->Initialize();
  vtkNew<vtkOpenVRRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);

  vtkNew<vtkOpenVRRenderer> renderer;
  renderWindow->AddRenderer(renderer);
  vtkNew<vtkNamedColors> namedColors;
  renderer->SetBackground(namedColors->GetColor3d("ForestGreen").GetData());
  renderer->AddVolume(volume);
  volume->SetPosition(0, 0.5, 0);

  renderWindow->Render();
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(OpenVRVolume)

find_package(VTK COMPONENTS 
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "OpenVRVolume: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
add_executable(OpenVRVolume MACOSX_BUNDLE OpenVRVolume.cxx )
  target_link_libraries(OpenVRVolume PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS OpenVRVolume
  MODULES ${VTK_LIBRARIES}
)

Download and Build OpenVRVolume

Click here to download OpenVRVolume and its CMakeLists.txt file. Once the tarball OpenVRVolume.tar has been downloaded and extracted,

cd OpenVRVolume/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:

./OpenVRVolume

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.