[vtkusers] Accessing p-skeleton

[Sensei]

Hi everybody!

I am writing a fairly simple program to try things. I'd like to store 
the entire topology of a cell complex, and as far as I understand I 
should use the vtkCellArray class.

So what I wrote is simple: create a triangle. I started from the 
example, so I added cell by cell, just to be sure. (see the code below) I

Now it works, and I correctly get the number of cells as 7 (1 2-cell, 3 
1-cells, and 3 0-cells).

How can I access them, collectively? For example "give me the 
0-skeleton" (all the points).

I have the impression I am misusing VTK here, and there is a kosher way 
of achieving this. In the future, I'll need this facility to pick cells 
of a certain dimension with the mouse.

Any hints?


Thanks & Cheers!



PS. By the way, after adding a new actor, how can I force an update? It 
doesn't appear until I manipulate the window (for example panning or 
rotating the view).





         double pts[3][3] =
         {
             { 0.0, 0.0, 0.0 },
             { 1.0, 0.0, 0.0 },
             { 0.0, 1.0, 0.0 }
         };

         vtkIdType k_0[3][1] =
         {
             { 0 },
             { 1 },
             { 2 }
         };

         vtkIdType k_1[3][2] =
         {
             { 0, 1 },
             { 1, 2 },
             { 2, 0 }
         };

         vtkIdType k_2[1][3] =
         {
             { 0, 1, 2 }
         };

         vtkSmartPointer<vtkPolyData> poly = 
vtkSmartPointer<vtkPolyData>::New();

         // K_0
         vtkSmartPointer<vtkPoints> points = 
vtkSmartPointer<vtkPoints>::New();
         points->InsertPoint(0, pts[0]);
         points->InsertPoint(1, pts[1]);
         points->InsertPoint(2, pts[2]);

         poly->SetPoints(points);

         vtkSmartPointer<vtkCellArray> cells = 
vtkSmartPointer<vtkCellArray>::New();
         // K_0
         cells->InsertNextCell(1, k_0[0]);
         cells->InsertNextCell(1, k_0[1]);
         cells->InsertNextCell(1, k_0[2]);
         // K_1
         cells->InsertNextCell(2, k_1[0]);
         cells->InsertNextCell(2, k_1[1]);
         cells->InsertNextCell(2, k_1[2]);
         // K_2
         cells->InsertNextCell(3, k_2[0]);

         poly->SetPolys(cells);

         vtkSmartPointer<vtkPolyDataMapper> map = 
vtkSmartPointer<vtkPolyDataMapper>::New();
         map->SetInput(poly);
         map->Update();

         vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
         actor->SetMapper(map);

         renderer3d_->AddActor(actor);

         qWarning("> adding poly: %lld", cells->GetNumberOfCells());