glTF Write Sample

//start_of_maingltfmeshwritemain
 
 
 
//! \brief Sample 1: writes a cube and a cylinder mesh in a two-node hierarchy into a GLTF file.
Dtk_ErrorStatus GltfwTwoMeshes( const Dtk_string& inOutputFileName )
{ // SAMPLE 1
     Dtk_MeshPtr CubeMesh, CylinderMesh;
     Dtk_bool useless; // useless for this sample
     // Cube Sample
     CubeMesh = sampleWriter::CreateMeshCube();
     // Cylinder Sample
     CylinderMesh = sampleWriter::CreateMeshCylinder( 30 );
 
     DtkErrorStatus err = dtkNoError;
     // First we initialize writing with name of files and protection fonction if needed (3rd parameter)
     Dtk_GltfWriter gltfWriter( inOutputFileName, err );
     if( err != dtkNoError )
          return err;
 
     // Rootnode creation
     gltfWriter.OpenInstance( "RootNode", -1, useless );
 
     // from this node, create a Child for the cube, and naming it "Cube"
     gltfWriter.OpenInstance( "Cube", -1, useless );
     // write the cube
     gltfWriter.WriteMesh( CubeMesh );
 
     // close the cube node
     gltfWriter.CloseLastInstance();
 
     // from root node again, create a Child for the cylinder, and naming it "Cylinder"
     gltfWriter.OpenInstance( "Cylinder", -1, useless );
     // write the cube
     gltfWriter.WriteMesh( CylinderMesh );
     // close the cube node
     gltfWriter.CloseLastInstance();
 
     // Rootnode closing.
     gltfWriter.CloseLastInstance();
 
     return dtkNoError;
}
 
 
//! \brief Sample 2: writes 10 re-instanced cubes and a wireframe mesh into a GLTF file, demonstrating geometry instancing.
Dtk_ErrorStatus GltfwInstances( const Dtk_string& inOutputFileName )
{ // SAMPLE 2
     Dtk_MeshPtr CubeMesh;
     Dtk_MeshPtr WireMesh;
     // Cube Sample
     CubeMesh = sampleWriter::CreateMeshCube();
     WireMesh = sampleWriter::CreateMeshWire();
     Dtk_transfo cubetransfo;
     Dtk_bool useless, isNewNode; // unused in this sample
 
     // For this sample, we write 10 instances of cube.
     // the matrix given is shifted in all iterations
     // Inside the for below, we give an ID to OpenInstance. Then we add the cube, and close the child.
     // For all others instances, we give the same ID to OpenInstance, and just close the child. Gltf Writer will recognize the ID and automatic reinstance the cube with another matrix.
     DtkErrorStatus err = dtkNoError;
     // First we initialize writing with name of files and protection fonction if needed (3rd parameter)
     Dtk_GltfWriter gltfWriter( inOutputFileName, err );
     if( err != dtkNoError )
          return err;
     gltfWriter.OpenInstance( "RootNode", -1, useless );
     int instanceIdx;
     for( instanceIdx = 0; instanceIdx < 10; instanceIdx++ )
     {
          gltfWriter.OpenInstance( "Cube", 1, isNewNode, cubetransfo ); // Giving ID 1
          if( isNewNode )
          {
               gltfWriter.WriteMesh( CubeMesh );
          }
          gltfWriter.CloseLastInstance();
          cubetransfo.addTranslate( Dtk_dir( 10, 0, 0 ) ); // shift matrix.
     }
     gltfWriter.OpenInstance("WireMesh", 2, isNewNode, Dtk_transfo()); // Giving ID 2
     if (isNewNode)
     {
          gltfWriter.WriteMesh(WireMesh);
     }
     gltfWriter.CloseLastInstance();
 
     gltfWriter.CloseLastInstance();
     return dtkNoError;
}
 
DtkErrorStatus
GltfWriteSample( const Dtk_string &inResultDirectory )
{
     Dtk_string outputDirectory, fileName;
     std::cout << std::endl << "----------------------------------------------" << std::endl;
 
     // Choosing output directory and file name
     outputDirectory = inResultDirectory + L"Gltf/";
     outputDirectory.FixPathSeparator();
     outputDirectory.mkdir();
 
     std::cout << "Gltf Write start" << std::endl;
     std::cout << "sample 1" << std::endl;
     // sample 1 : just write 2 meshes
     fileName = outputDirectory + L"twomeshes.gltf";
     Dtk_ErrorStatus errorStatus = GltfwTwoMeshes( fileName );
     if( errorStatus == dtkNoError )
          std::cout << "=> " << fileName.c_str() << std::endl;
     else
          std::cout << "error : " << dtkTypeError( errorStatus ).c_str() << std::endl;
 
     std::cout << "sample 2" << std::endl;
     // sample 2 : write instances
     fileName = outputDirectory + L"instances.gltf";
     errorStatus = GltfwInstances( fileName );
     if( errorStatus == dtkNoError )
          std::cout << "=> " << fileName.c_str() << std::endl;
     else
          std::cout << "error : " << dtkTypeError( errorStatus ).c_str() << std::endl;
 
     std::cout << "Gltf Write end" << std::endl;
 
     return errorStatus;
}
//end_of_maingltfmeshwrite