单元绑定旧方法

     //单元类型列表
    vtkIdTypeArray* cellInfoList = vtkIdTypeArray::New();
    cellInfoList->SetNumberOfValues((numCellPnts + 1) * numberCells);
    vtkIdType* cellInforPtr = cellInfoList->GetPointer(0);
//单元列表
    vtkUnsignedCharArray* cellTypeList = vtkUnsignedCharArray::New();
    cellTypeList->SetNumberOfValues(numberCells);
    unsigned char* cellTypesPtr = cellTypeList->GetPointer(0);

    for (int c = 0; c < numberCells; c++)
    {
               //单元类型
        *cellTypesPtr++ = VTK_CellType;
                //单元点数
        *cellInforPtr++ = numCellPnts;

        for (int j = 0; j < numCellPnts; j++)
        {
                         //点
            //*cellInforPtr++ = pointID
        }
    }
    cellInforPtr = nullptr;
    cellTypesPtr = nullptr;

    // 单元数组
    vtkCellArray* theCellArray = vtkCellArray::New();
    theCellArray->ImportLegacyFormat(cellInfoList);
    cellInfoList->Delete();
    cellInfoList = nullptr;

    // 绑定单元
    unstrctGrid->SetCells(cellTypeList, theCellArray);
    theCellArray->Delete();
    cellTypeList->Delete();
    theCellArray = nullptr;
    cellTypeList = nullptr;

vtk单元类型：https://blog.csdn.net/calmreason/article/details/124268501
新的填充方式相对于，创建单元对象的方式效率更高，比绑定单元的方式更灵活。
vtk新的填充单元方式（非多面体）

vtkNew<vtkUnstructuredGrid> unstruct;
std::vector<std::vector>cells;//单元和点id
unstruct->Allocate(cells.size());//初始化单元大小
for (int i = 0 ;i< cells.size();i++)
{
   vtkNew<vtkIdList> cellIDdList;//填充单元点id数据
   for (int curri = 0; curri < cells[i].size(); curri++)
  {
     cellIDdList->InsertNextId(cells[i][curri]);
  }
  unstruct->InsertNextCell(VTK_POLYGON, cellIDdList->GetNumberOfIds(), cellIDdList->GetPointer(0));//填充单元，1.单元类型，2.单元点数，3数据指针
}

vtk新的填充单元方式（多面体）
多面体单元数据需要面和点，点构成面，面构成体。

    vtkNew<vtkUnstructuredGrid> unstruct;
    std::vector<std::vector<vtkIdType>> cells;//每个单元的面id数据
    std::vector<std::vector<vtkIdType>> faces;//每个面的点id数据
    unstruct->Allocate(cells.size());//初始化单元大小
    for (int i = 0; i < cells.size();i++)
    {
        const auto& cell = cells[i];
        vtkNew<vtkIdList> polyhedron;
        for (auto& aFaceIndex : cell )
        {
            const auto& aFace = faces[aFaceIndex];
            const auto faceSize = static_cast<vtkIdType>(aFace.size());//每个面点数
            polyhedron->InsertNextId(faceSize);
            for (auto& aVertexIndex : aFace)
            {
                polyhedron->InsertNextId(aVertexIndex);//填充点id数据
            }
        }
        unstruct->InsertNextCell(VTK_POLYHEDRON, cell .size(), polyhedron->GetPointer(0));//填充单元数据，2.面的数量，单元数据指针。
    }