# OpenVRSphere

VTKExamples/Cxx/GeometricObjects/OpenVRSphere

### Description

This example demonstrates rendering of Sphere in OpenVR (HTC Head-Mounted Display).

### Code

OpenVRSphere.cxx

    #include <vtkSphereSource.h>
    #include <vtkPolyData.h>
    #include <vtkSmartPointer.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkNamedColors.h>
    #include <vtkOpenVRRenderWindow.h>
    #include <vtkOpenVRRenderer.h>
    #include <vtkOpenVRRenderWindowInteractor.h>
    //Author: Chethana B
    //Organisation: Virtual Environments Lab, Chung Ang University, Seoul, South Korea.
    int main(int, char *[])
    {
      // Create a Sphere
      vtkSmartPointer<vtkSphereSource> sphereSource = vtkSmartPointer<vtkSphereSource>::New();
      sphereSource->SetCenter(0.0, 0.0, 0.0);
      sphereSource->SetRadius(5.0);

      //Create a Mapper
      vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(sphereSource->GetOutputPort());

      //Create an Actor
      vtkSmartPointer<vtkNamedColors> colors = vtkSmartPointer<vtkNamedColors>::New();
      vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);

      //Create a Renderer, RenderWindow, RenderWindowInteractor
      vtkSmartPointer<vtkOpenVRRenderer> renderer = vtkSmartPointer<vtkOpenVRRenderer>::New();
      vtkSmartPointer<vtkOpenVRRenderWindow> renderWindow = vtkSmartPointer<vtkOpenVRRenderWindow>::New();
      renderWindow->AddRenderer(renderer);
      vtkSmartPointer<vtkOpenVRRenderWindowInteractor> renderWindowInteractor =  vtkSmartPointer<vtkOpenVRRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      //Add actor to the scene
      renderer->AddActor(actor);
      renderer->SetBackground(colors->GetColor3d("ForestGreen").GetData());
      renderWindow->Render();
      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(OpenVRSphere)

    find_package(VTK COMPONENTS
      vtkCommonColor
      vtkCommonCore
      vtkCommonDataModel
      vtkFiltersSources
      vtkInteractionStyle
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingOpenGL2
      vtkRenderingOpenVR QUIET)
    if (NOT VTK_FOUND)
      message("Skipping OpenVRSphere: ${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(OpenVRSphere MACOSX_BUNDLE OpenVRSphere.cxx )
      target_link_libraries(OpenVRSphere PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(OpenVRSphere MACOSX_BUNDLE OpenVRSphere.cxx )
      target_link_libraries(OpenVRSphere PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS OpenVRSphere
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build OpenVRSphere

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

    cd OpenVRSphere/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:

    ./OpenVRSphere

WINDOWS USERS

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