GLTFImporter

VTKExamples/Cxx/IO/GLTFImporter

The example uses vtkGLTFImporter to import a scene from a gltf file. glTF (derivative short form of GL Transmission Format) is a file format for 3D scenes and models using the JSON standard. It is an API-neutral runtime asset delivery format developed by the Khronos Group 3D Formats Working Group. It was announced at HTML5DevConf 2016.

There are many sources of glTF file including:

usage

GLTFImporter FlightHelmet.gltf

Warning

When you run the example, be sure to specify the full pathname of the .glTF file. There is currently a bug in the vtkGLTFImporter. For example, if your home directry is /home/janedoe the the full pathname of the FlightHelmet data is /home/janedoe/VTKExamples/src/Testing/Data/gltf/FlightHelmet/FlightHelmet.gltf.

Warning

The gltf files are stored using git's lfs large file system. If you do not have git lfs installed, you may access the FlightHelmet Data) directly from the orignal repo. Be sure to download all of the files.

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

GLTFImporter.cxx

#include <vtkSmartPointer.h>
#include <vtkGLTFImporter.h>

#include <vtkCamera.h>
#include <vtkLight.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkRenderer.h>
#include <vtkNamedColors.h>

int main(int argc, char* argv[])
{
  if (argc <= 1)
  {
    std::cout << "Usage: " << argv[0] << " <gltf file>" << std::endl;
    return EXIT_FAILURE;
  }

  auto colors =
    vtkSmartPointer<vtkNamedColors>::New();

  vtkColor3d backgroundColor = colors->GetColor3d("SlateGray");

  auto importer =
    vtkSmartPointer<vtkGLTFImporter>::New();
  importer->SetFileName(argv[1]);

  auto renderer =
    vtkSmartPointer<vtkRenderer>::New();
  renderer->SetBackground(backgroundColor.GetData());
  renderer->UseHiddenLineRemovalOn();

  auto renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->SetSize(640, 512);
  renderWindow->AddRenderer(renderer);

  auto renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);
  auto style =
    vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New();
  renderWindowInteractor->SetInteractorStyle(style);

  importer->SetRenderWindow(renderWindow);
  importer->Update();

  auto headLight =
    vtkSmartPointer<vtkLight>::New();
  headLight->SetLightTypeToHeadlight();
  headLight->SwitchOn();
  renderer->AddLight(headLight);

  renderWindow->Render();
  renderer->ResetCamera();
  renderer->GetActiveCamera()->Azimuth(20);
  renderer->GetActiveCamera()->Elevation(30);
  renderer->ResetCameraClippingRange();

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

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(GLTFImporter)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkIOImport
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping GLTFImporter: ${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(GLTFImporter MACOSX_BUNDLE GLTFImporter.cxx )
  target_link_libraries(GLTFImporter PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(GLTFImporter MACOSX_BUNDLE GLTFImporter.cxx )
  target_link_libraries(GLTFImporter PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS GLTFImporter
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build GLTFImporter

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

cd GLTFImporter/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:

./GLTFImporter

WINDOWS USERS

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