vtk代码生成网格文件

为了研究vtk文件的格式需要代码生成vtk文件，生成文件的c++代码如下：

1 int writeVtkFile() {
  2     vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
  3     points->InsertNextPoint(0.0, 0.0, 0.0);
  4     points->InsertNextPoint(1.0, 0.0, 0.0);
  5     points->InsertNextPoint(1.0, 1.0, 0.0);
  6     points->InsertNextPoint(0.0, 1.0, 0.0);
  7 
  8     points->InsertNextPoint(0.0, 0.0, 1.0);
  9     points->InsertNextPoint(1.0, 0.0, 1.0);
 10     points->InsertNextPoint(1.0, 1.0, 1.0);
 11     points->InsertNextPoint(0.0, 1.0, 1.0);
 12 
 13 
 14     vtkSmartPointer<vtkPolygon> polygon1 = vtkSmartPointer<vtkPolygon>::New();
 15     polygon1->GetPointIds()->SetNumberOfIds(4);
 16     polygon1->GetPointIds()->SetId(0, 0);
 17     polygon1->GetPointIds()->SetId(1, 1);
 18     polygon1->GetPointIds()->SetId(2, 2);
 19     polygon1->GetPointIds()->SetId(3, 3);
 20 
 21     vtkSmartPointer<vtkPolygon> polygon2 = vtkSmartPointer<vtkPolygon>::New();
 22     polygon2->GetPointIds()->SetNumberOfIds(4);
 23     polygon2->GetPointIds()->SetId(0, 4);
 24     polygon2->GetPointIds()->SetId(1, 5);
 25     polygon2->GetPointIds()->SetId(2, 6);
 26     polygon2->GetPointIds()->SetId(3, 7);
 27 
 28     vtkSmartPointer<vtkPolygon> polygon3 = vtkSmartPointer<vtkPolygon>::New();
 29     polygon3->GetPointIds()->SetNumberOfIds(4);
 30     polygon3->GetPointIds()->SetId(0, 0);
 31     polygon3->GetPointIds()->SetId(1, 1);
 32     polygon3->GetPointIds()->SetId(2, 5);
 33     polygon3->GetPointIds()->SetId(3, 4);
 34 
 35     vtkSmartPointer<vtkPolygon> polygon4 = vtkSmartPointer<vtkPolygon>::New();
 36     polygon4->GetPointIds()->SetNumberOfIds(4);
 37     polygon4->GetPointIds()->SetId(0, 1);
 38     polygon4->GetPointIds()->SetId(1, 2);
 39     polygon4->GetPointIds()->SetId(2, 6);
 40     polygon4->GetPointIds()->SetId(3, 5);
 41 
 42     vtkSmartPointer<vtkPolygon> polygon5 = vtkSmartPointer<vtkPolygon>::New();
 43     polygon5->GetPointIds()->SetNumberOfIds(4);
 44     polygon5->GetPointIds()->SetId(0, 2);
 45     polygon5->GetPointIds()->SetId(1, 3);
 46     polygon5->GetPointIds()->SetId(2, 7);
 47     polygon5->GetPointIds()->SetId(3, 6);
 48 
 49     vtkSmartPointer<vtkPolygon> polygon6 = vtkSmartPointer<vtkPolygon>::New();
 50     polygon6->GetPointIds()->SetNumberOfIds(4);
 51     polygon6->GetPointIds()->SetId(0, 3);
 52     polygon6->GetPointIds()->SetId(1, 0);
 53     polygon6->GetPointIds()->SetId(2, 4);
 54     polygon6->GetPointIds()->SetId(3, 7);
 55 
 56 
 57     vtkSmartPointer<vtkCellArray> polycells = vtkSmartPointer<vtkCellArray>::New();
 58     polycells->InsertNextCell(polygon1);
 59     polycells->InsertNextCell(polygon2);
 60     polycells->InsertNextCell(polygon3);
 61     polycells->InsertNextCell(polygon4);
 62     polycells->InsertNextCell(polygon5);
 63     polycells->InsertNextCell(polygon6);
 64 
 65     vtkSmartPointer<vtkPolyData> polyData = vtkSmartPointer<vtkPolyData>::New();
 66     polyData->SetPoints(points);
 67     polyData->SetPolys(polycells);
 68 
 69 
 70     vtkSmartPointer<vtkDoubleArray> pressure = vtkSmartPointer<vtkDoubleArray>::New();
 71     pressure->SetNumberOfValues(8);
 72     pressure->SetValue(0, 0);
 73     pressure->SetValue(1, 1);
 74     pressure->SetValue(2, 2);
 75     pressure->SetValue(3, 3);
 76     pressure->SetValue(4, 4);
 77     pressure->SetValue(5, 3);
 78     pressure->SetValue(6, 2);
 79     pressure->SetValue(7, 1);
 80     pressure->SetName("pressure");
 81 
 82     vtkSmartPointer<vtkDoubleArray> temperature = vtkSmartPointer<vtkDoubleArray>::New();
 83     temperature->SetNumberOfValues(6);
 84     temperature->SetValue(0, 5);
 85     temperature->SetValue(1, 6);
 86     temperature->SetValue(2, 7);
 87     temperature->SetValue(3, 8);
 88     temperature->SetValue(4, 9);
 89     temperature->SetValue(5, 8);
 90     temperature->SetName("temperature");
 91 
 92     polyData->GetPointData()->AddArray(pressure);
 93     polyData->GetCellData()->AddArray(temperature);
 94 
 95 
 96     vtkSmartPointer<vtkPolyDataWriter> writer = vtkSmartPointer<vtkPolyDataWriter>::New();
 97     writer->SetFileName("test.vtk");
 98     writer->SetInputData(polyData);
 99     writer->Write();
100 
101     return 0;
102 }

生成的vtk文件内容如下：

1 # vtk DataFile Version 5.1
 2 vtk output
 3 ASCII
 4 DATASET POLYDATA
 5 POINTS 8 float
 6 0 0 0 1 0 0 1 1 0 
 7 0 1 0 0 0 1 1 0 1 
 8 1 1 1 0 1 1 
 9 POLYGONS 7 24
10 OFFSETS vtktypeint64
11 0 4 8 12 16 20 24 
12 CONNECTIVITY vtktypeint64
13 0 1 2 3 4 5 6 7 0 
14 1 5 4 1 2 6 5 2 3 
15 7 6 3 0 4 7 
16 CELL_DATA 6
17 FIELD FieldData 1
18 temperature 1 6 double
19 5 6 7 8 9 8 
20 POINT_DATA 8
21 FIELD FieldData 1
22 pressure 1 8 double
23 0 1 2 3 4 3 2 1

备注：

CONNECTIVITY：就是上述所有 cell 的点 ID 顺序地放到一个列表里。但仅仅这样是不行的，因为不能辨认出那些点组合形成了什么cell，这就是 offsets 的功能了。

OFFSETS：每个 cell 起始点对应在 connectivity 列表中索引。如上，offsets 还多出了一个数。最后一个数，是 connectivity 的长度值。

# vtk DataFile Version 5.1
FAXINY-Step-1-2
ASCII
DATASET UNSTRUCTURED_GRID
POINTS 5 double
0.0 0.0 0.0
1.0 0.0 0.0
1.0 1.0 0.0
0.0 1.0 0.0
0.5 0.2 1.0
CELLS 2 5
OFFSETS vtktypeint64
0 5 10
CONNECTIVITY vtktypeint64
0 1 2 3 4
CELL_TYPES 1
14

paraview软件查看节点上的属性pressure，效果如下：

paraview软件查看单元上的属性temperature，效果如下：

原文链接: https://www.cnblogs.com/chanyuantiandao/p/15196739.html

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