在 vtk 中，您可以使用 InsertNextCell (int type, vtkIdType npts, vtkIdType *ptIds) 将六角棱柱单元格添加到 vtkUnstructuredGrid >。这很好，但我想在 vtkUnstructuredGrid 中包含一个 heptagonal 和 octagonal 棱镜。单元格类型未在 vtk 中定义...
只是为了消除一些疑虑，我正在使用 c#，但是 c++ 或 python 示例足以将其转换为 C#.
回到问题上，我先把代码复制并稍作修改in this example获得体素(8 点和 celltype = 11)
vtkPoints points = vtkPoints.New();
points.InsertNextPoint(-1.0, -1.0, -1.0);
points.InsertNextPoint(1.0, -1.0, -1.0);
points.InsertNextPoint(1.0, 1.0, -1.0);
points.InsertNextPoint(-1.0, 1.0, -1.0);
points.InsertNextPoint(-1.0, -1.0, 1.0);
points.InsertNextPoint(1.0, -1.0, 1.0);
points.InsertNextPoint(1.0, 1.0, 1.0);
points.InsertNextPoint(-1.0, 1.0, 1.0);
vtkUnstructuredGrid unstructuredGrid1 = vtkUnstructuredGrid.New();
unstructuredGrid1.SetPoints(points);
int[] ptIds = new int[] { 0, 1, 2, 3, 4, 5, 6, 7 };
IntPtr ptIdsPointer = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(int)) * 8);
Marshal.Copy(ptIds, 0, ptIdsPointer, 8);
unstructuredGrid1.InsertNextCell(11, 8, ptIdsPointer);
Marshal.FreeHGlobal(ptIdsPointer);
// Create a mapper and actor
vtkDataSetMapper mapper = vtkDataSetMapper.New();
mapper.SetInputConnection(unstructuredGrid1.GetProducerPort());
vtkActor actor = vtkActor.New();
actor.SetMapper(mapper);
actor.GetProperty().SetColor(1, 0, 0);
actor.GetProperty().SetPointSize(3);
actor.GetProperty().SetOpacity(1);
actor.GetProperty().SetLineWidth(2);
actor.GetProperty().EdgeVisibilityOn();
Renderer3D.AddActor(actor);
正确显示体素得到:
但因为我想要一个七面体，所以我尝试使用 VTK_POLYHEDRON 来调整这个想法，更改告诉类型 pf 单元格添加到非结构化网格的行
unstructuredGrid1.InsertNextCell(11, 8, ptIdsPointer);
到(42代表VTK_POLYHEDRON，11代表VTK_VOXEL)和points = 14
unstructuredGrid1.InsertNextCell(42, 14, ptIdsPointer);
喜欢this example .我尝试了类似 C++ 的方法，但没有得到任何结果
int numberOfVertices = 14;
int numberOfFaces = 9; //how to tell heptagonal prism has 2 faces with 7 vertices and 7 with 4 vertices?
int numberOfFaceVertices = 4;
vtkIdType heptagonPointsIds[14] =
{0, 1, 2, 3, 4, 5, 6
7, 8, 9, 10, 11, 12,13};
//points that only change in z
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
points->InsertNextPoint(454.6, 678.534, 1.1009301757813); //id 0
points->InsertNextPoint(454.6, 678.545, 1.1500146484375);//id 1
points->InsertNextPoint(454.6, 678.556, 1.2255187988281);//id 2
points->InsertNextPoint(455.1, 678.556, 1.6478076171875);//id 3
points->InsertNextPoint(455.1, 678.534, 1.7926538085938);//id 4
points->InsertNextPoint(455.1, 678.545, 1.7166479492188);//id 5
points->InsertNextPoint(454.85, 678.534, 1.0092297363281);//id 6
points->InsertNextPoint(454.6, 678.534, 5.1009301757813);//id 7
points->InsertNextPoint(454.6, 678.545, 5.1500146484375);//id 8
points->InsertNextPoint(454.6, 678.556, 5.2255187988281);//id 9
points->InsertNextPoint(455.1, 678.556, 5.6478076171875);//id 10
points->InsertNextPoint(455.1, 678.534, 5.7926538085938);//id 11
points->InsertNextPoint(455.1, 678.545, 5.7166479492188);//id 12
points->InsertNextPoint(454.85, 678.534, 5.0092297363281);//id13
vtkIdType heptagonPrismFace[9][4] = {
{0, 1, 7, 8},
{1, 2, 8, 9},
{2, 3, 9, 10},
{3, 4, 10, 11},
{4, 5, 11, 12},
{5, 6, 12, 13},
{6, 1, 13, 8},
//last two faces how to tel they should be 0 1 2 3 4 5 6 and 7 8 9 10 11 12 13 ?
{0, 1, 2, 3},
{7, 8, 9, 10},
};
vtkSmartPointer<vtkCellArray> heptagonFaces=
vtkSmartPointer<vtkCellArray>::New();
for (int i = 0; i < numberOfFaces; i++)
{
heptagonFaces->InsertNextCell(numberOfFaceVertices, heptagonPrismFace[i]);
}
vtkSmartPointer<vtkUnstructuredGrid> uGrid = vtkSmartPointer<vtkUnstructuredGrid>::New();
uGrid->InsertNextCell(VTK_POLYHEDRON,
numberOfVertices, heptagonPointsIds,
numberOfFaces, heptagonFaces->GetPointer());
uGrid->SetPoints(points);
vtkSmartPointer<vtkDataSetMapper> mapper = vtkSmartPointer<vtkDataSetMapper>::New();
mapper->SetInputConnection(uGrid->GetProducerPort());
//add actor to render and stuff...
我怎样才能得到像图像这样的东西:
最佳答案
使用 vtkLinearExtrusionFilter 更容易。我写了一些 C++ 代码来生成具有可变边的多边形棱镜。我希望这会有所帮助:
vtkSmartPointer<vtkVectorText> vecText =
vtkSmartPointer<vtkVectorText>::New();
vecText->SetText("Text!");
vecText->Update();
vtkSmartPointer<vtkPoints> points =
vtkSmartPointer<vtkPoints>::New();
double Radius=1;
int NumberOfSides=7;
for (int i=0;i<NumberOfSides;i++)
points->InsertNextPoint(Radius*cos((double)i*2*vtkMath::Pi()/NumberOfSides), Radius*sin((double)i*2*vtkMath::Pi()/NumberOfSides), 0.0);
// Create the polygon
vtkSmartPointer<vtkPolygon> polygon =
vtkSmartPointer<vtkPolygon>::New();
polygon->GetPointIds()->SetNumberOfIds(NumberOfSides);
for(int i=0;i<NumberOfSides;i++)
polygon->GetPointIds()->SetId(i, i);
// Add the polygon to a list of polygons
vtkSmartPointer<vtkCellArray> polygons =
vtkSmartPointer<vtkCellArray>::New();
polygons->InsertNextCell(polygon);
// Create a PolyData
vtkSmartPointer<vtkPolyData> polygonPolyData =
vtkSmartPointer<vtkPolyData>::New();
polygonPolyData->SetPoints(points);
polygonPolyData->SetPolys(polygons);
// Apply linear extrusion
vtkSmartPointer<vtkLinearExtrusionFilter> extrude =
vtkSmartPointer<vtkLinearExtrusionFilter>::New();
extrude->SetInputData( polygonPolyData);
extrude->SetExtrusionTypeToNormalExtrusion();
extrude->SetVector(0, 0, 1 );
extrude->SetScaleFactor (2);
extrude->Update();
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
vtkSmartPointer<vtkPolyDataMapper> mapper=vtkSmartPointer<vtkPolyDataMapper>::New();
vtkSmartPointer<vtkActor> actor=vtkSmartPointer<vtkActor>::New();
mapper->SetInputData( extrude->GetOutput());
actor->SetMapper(mapper);
vtkSmartPointer<vtkRenderer> renderer=vtkSmartPointer<vtkRenderer>::New();
renderer->AddActor(actor);
renderWindow->AddRenderer(renderer);
vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New();
renderWindow->SetInteractor( renderWindowInteractor);
renderWindow->Render();
我运行了代码并得到了这个七棱柱的 3d 形状:
关于c# - 如何创建vtk七角棱柱(7个面4个顶点和2个面7个顶点)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35932279/