ImportToExport

Description¶

This example imports one of vtk3DSImporter, vtkGLTFImporter, vtkOBJImporter or vtkVRMLImporter and exports the scene using one of vtkOBJExporter

The parameters are the input file(s) and an export file name with extension.

Question

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

Code¶

ImportToExport.cxx

#include <vtkNew.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>

// Importers
#include <vtk3DSImporter.h>
#include <vtkGLTFImporter.h>
#include <vtkOBJImporter.h>
#include <vtkVRMLImporter.h>

// Exporters
#include <vtkGLTFExporter.h>
// #include <vtkIVExporter.h>
#include <vtkOBJExporter.h>
// #include <vtkOOGLExporter.h>
// #include <vtkRIBExporter.h>
// #include <vtkSVGExporter.h>
#include <vtkVRMLExporter.h>
#include <vtkX3DExporter.h>

#include <algorithm> // For transform()
#include <cctype>    // For to_lower
#include <iterator>  // For prev
#include <set>       // For valid extensions
#include <sstream>   // For stringstream
#include <string>    // For find_last_of()

int main(int argc, char* argv[])
{
  auto renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
  auto renderer = vtkSmartPointer<vtkRenderer>::New();

  if (argc < 3)
  {
    std::cerr << "Expects input file name(s) and an output filename e.g. "
                 "iflamingo.3ds iflamingo.obj"
              << std::endl;
    return EXIT_FAILURE;
  }

  std::string fileName = argv[1];
  std::string extension = "";
  int outputFileArgOffset = 0; // depends on importer

  std::set<std::string> inputExtensions{{
      "3ds",
      "glb",
      "gltf",
      "obj",
      "wrl",
  }};
  std::set<std::string> outputExtensions{{
      "glb",
      "gltf",
      "obj",
      "wrl",
      "x3d",
  }};

  // Make the extension lowercase
  std::transform(extension.begin(), extension.end(), extension.begin(),
                 ::tolower);
  if (fileName.find_last_of(".") != std::string::npos)
  {
    extension = fileName.substr(fileName.find_last_of(".") + 1);
  }
  if (inputExtensions.find(extension) == inputExtensions.end())
  {
    std::cout << "Invalid input extension.\nValid extensions are: "
              << std::endl;
    for (auto it = inputExtensions.begin(); it != inputExtensions.end(); ++it)
    {
      if (it != std::prev(inputExtensions.end()))
      {
        std::cout << *it << ", ";
      }
      else
      {
        std::cout << *it << std::endl;
      }
    }
    return EXIT_FAILURE;
  }

  if (extension == "wrl")
  {
    vtkNew<vtkVRMLImporter> importer;
    importer->SetFileName(argv[1]);
    importer->SetRenderWindow(renderWindow);
    renderWindow = importer->GetRenderWindow();
    renderer = importer->GetRenderer();
    importer->Read();
    outputFileArgOffset = 2;
  }
  else if (extension == "3ds")
  {
    vtkNew<vtk3DSImporter> importer;
    importer->SetFileName(argv[1]);
    importer->SetRenderWindow(renderWindow);
    importer->ComputeNormalsOn();
    renderWindow = importer->GetRenderWindow();
    renderer = importer->GetRenderer();
    importer->Read();
    outputFileArgOffset = 2;
  }
  else if (extension == "gltf" || extension == "glb")
  {
    vtkNew<vtkGLTFImporter> importer;
    importer->SetFileName(argv[1]);
    importer->SetRenderWindow(renderWindow);
    renderWindow = importer->GetRenderWindow();
    renderer = importer->GetRenderer();
    importer->Read();
    outputFileArgOffset = 2;
  }
  else if (extension == "obj")
  {
    vtkNew<vtkOBJImporter> importer;
    importer->SetFileName(argv[1]);
    importer->SetFileNameMTL(argv[2]);
    importer->SetTexturePath(argv[3]);
    importer->SetRenderWindow(renderWindow);
    renderWindow = importer->GetRenderWindow();
    renderer = importer->GetRenderer();
    importer->Read();
    outputFileArgOffset = 4;
  }

  std::string outputFileName = argv[outputFileArgOffset];
  std::string outputExtension{""};
  // Split the file path and extension
  if (outputFileName.find_last_of(".") != std::string::npos)
  {
    outputExtension =
        outputFileName.substr(outputFileName.find_last_of(".") + 1);
    auto pos = outputFileName.rfind(".", outputFileName.length());
    if (pos != std::string::npos)
    {
      outputFileName = outputFileName.substr(0, pos);
    }
  }
  std::transform(outputExtension.begin(), outputExtension.end(),
                 outputExtension.begin(), ::tolower);

  if (outputExtensions.find(outputExtension) == outputExtensions.end())
  {
    std::cout << "Invalid output extension.\nValid extensions are: "
              << std::endl;
    for (auto it = outputExtensions.begin(); it != outputExtensions.end(); ++it)
    {
      if (it != std::prev(outputExtensions.end()))
      {
        std::cout << *it << ", ";
      }
      else
      {
        std::cout << *it << std::endl;
      }
    }
    return EXIT_FAILURE;
  }

  if (outputExtension == "obj")
  {
    std::string exportFileName;
    exportFileName = outputFileName + "." + outputExtension;
    vtkNew<vtkOBJExporter> exporter;
    std::stringstream comment;
    comment << "Converted by ImportExport from " << fileName;
    exporter->SetOBJFileComment(comment.str().c_str());
    exporter->SetMTLFileComment(comment.str().c_str());
    exporter->SetActiveRenderer(renderer);
    exporter->SetRenderWindow(renderWindow);
    exporter->SetFilePrefix(outputFileName.c_str());
    std::cout << "Writing " << exportFileName << std::endl;
    exporter->Write();
  }
  else if (outputExtension == "wrl")
  {
    std::string exportFileName;
    exportFileName = outputFileName + "." + outputExtension;
    vtkNew<vtkVRMLExporter> exporter;
    exporter->SetFileName(exportFileName.c_str());
    exporter->SetActiveRenderer(renderer);
    exporter->SetRenderWindow(renderWindow);
    std::cout << "Writing " << exportFileName << std::endl;
    exporter->Write();
  }
  else if (outputExtension == "gltf" || outputExtension == "glb")
  {
    std::string exportFileName;
    exportFileName = outputFileName + "." + "gltf";
    vtkNew<vtkGLTFExporter> exporter;
    exporter->SetFileName(exportFileName.c_str());
    exporter->SetActiveRenderer(renderer);
    exporter->SetRenderWindow(renderWindow);
    std::cout << "Writing " << exportFileName << std::endl;
    exporter->Write();
  }
  else if (outputExtension == "x3d")
  {
    std::string exportFileName;
    exportFileName = outputFileName + "." + outputExtension;
    vtkNew<vtkX3DExporter> exporter;
    exporter->SetFileName(exportFileName.c_str());
    exporter->SetActiveRenderer(renderer);
    exporter->SetRenderWindow(renderWindow);
    std::cout << "Writing " << exportFileName << std::endl;
    exporter->Write();
  }

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(ImportToExport)

find_package(VTK COMPONENTS 
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "ImportToExport: 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(ImportToExport MACOSX_BUNDLE ImportToExport.cxx )
  target_link_libraries(ImportToExport PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS ImportToExport
  MODULES ${VTK_LIBRARIES}
)

Download and Build ImportToExport¶

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

cd ImportToExport/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:

./ImportToExport

WINDOWS USERS

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