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GLTFImporter

vtk-examples/Cxx/IO/GLTFImporter


Description

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.

Info

The original data can be found here: FlightHelmet Data). Be sure to download all of the files.

Question

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

Code

GLTFImporter.cxx

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

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

  vtkNew<vtkNamedColors> colors;

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

  vtkNew<vtkGLTFImporter> importer;
  importer->SetFileName(argv[1]);

  vtkNew<vtkRenderer> renderer;
  renderer->SetBackground(backgroundColor.GetData());
  renderer->UseHiddenLineRemovalOn();

  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->SetSize(640, 512);
  renderWindow->AddRenderer(renderer);
  renderWindow->SetWindowName("GLTFImporter");

  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);
  vtkNew<vtkInteractorStyleTrackballCamera> style;
  renderWindowInteractor->SetInteractorStyle(style);

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

  vtkNew<vtkLight> headLight;
  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 3.12 FATAL_ERROR)

project(GLTFImporter)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  IOImport
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "GLTFImporter: 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(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}
)

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.