如何将网格转换为VTK格式？

Question

我有自己格式的网格,我想将它导出到.vtk文件.我该怎么做呢？

原始网格采用以下格式:(伪代码)

class Mesh {

   List<Float[3]> _coordinates

   List<int[4]> _tetra //(elements, Faces, etc.)

}

我希望这能澄清我的问题.我只想用Paraview加载它,所以我不在乎它是否是结构化的,聚合等.

Answer 1

您可以创建一个vtkUnstructuredGrid:

//vtkPolyData *data = vtkPolyData::New();
vtkUnstructuredGrid *mesh = vtkUnstructuredGrid::New();
vtkPoints *points = vtkPoints::New();
vtkCellArray *cells = vtkCellArray::New();

//vtkIdType pointIDs[4];

std::vector<point>::const_iterator iterator1 = fpoints.begin();

point aux;

if ( event_report != NULL ) { event_report->SetMaxTicks(fpoints.size() + fnodes.size()); }
points->SetNumberOfPoints(fpoints.size());
int pointId = 0;
for (;iterator1 != fpoints.end();iterator1++)
{
    aux = *iterator1;
    points->SetPoint(pointId, aux.coord);
    pointId++;
}

std::vector<node>::const_iterator iterator2 = fnodes.begin();

node aux1;

vtkSmartPointer<vtkIdTypeArray> idCells = 
  vtkSmartPointer<vtkIdTypeArray>::New();
idCells->SetNumberOfComponents(5);
idCells->SetNumberOfTuples(fnodes.size());

int cellIndex = 0;
for (;iterator2 != fnodes.end(); iterator2++)
{
    aux1 = *iterator2;
    vtkIdType * tuple = new vtkIdType[4];
    tuple[0] = 4;
    tuple[1] = aux1.indexs[0] - 1;
    tuple[2] = aux1.indexs[1] - 1;
    tuple[3] = aux1.indexs[2] - 1;
    tuple[4] = aux1.indexs[3] - 1;
    idCells->SetTupleValue(cellIndex, tuple);
    cellIndex++;
}
cells->SetCells(fnodes.size(), idCells);

mesh->SetPoints(points);
mesh->SetCells(VTK_TETRA, cells);

//vtkPolyDataWriter *writer = vtkPolyDataWriter::New();
vtkUnstructuredGridWriter *tetra_writer = vtkUnstructuredGridWriter::New();
tetra_writer->SetFileName( filename );

#if VTK_MAJOR_VERSION <= 5
    tetra_writer->SetInput(mesh);
#else
    tetra_writer->SetInputData(mesh);
#endif

tetra_writer->Write();
tetra_writer->Delete( );

Answer 2

查看meshio（我的一个项目），它将帮助您将网格从多种格式转换为多种格式（包括VTK）。VTK接口代码可以为您提供有关如何自定义它的线索。