[vtkusers] A simple question about vtkPolyData

[Sebastien_MARAUX]

try :

int index;
for (int i=0;i<vtkPolyData->GetNumberOfPolys();i++,index++) {

    // looking for polygon cells / quad cells or triangle cells, you can
remove some types if
    //you want but beware that you need to count the number of this special
type cells for the
    //loop, or getnumberofpolys will loop too far in the cell and a memory
error will occure.

    while (vtkPlyData->GetCellType(index) != VTK_POLYGON
            && (idem) != VTK_QUAD    //which is also a poly
            && (idem) != VTK_TRIANGLE   //idem, I can forget some types,
refer to vtkCellTypes
                                        //for more types
            ) index++;

    vtkIdList *points = vtkIdList::New();
    vtkPolyData::GetCellPoints(index, points);

// points contained in "points" are the current cell points, do whatever you
want with it.
// you can retrieve them by looping for points->GetNumberOfIds() in
// vtkPolyData->GetPoint(points->GetId(x)); for each polygon/quad/triangle
cell.
}

you can tweak this for use with get polys, which should be simpler:
once you have your cell array, you can loop in each cell and do the same job
:
loop for number of ids (getpointids) and do a getcellpoints on the
vtkpolydata


Hope this helps

Sebastien Maraux

----- Original Message -----
From: "Dai Shuo" <dai_shuocn at 163.com>
To: "vtk" <vtkusers at public.kitware.com>
Sent: Wednesday, June 05, 2002 3:12 AM
Subject: [vtkusers] A simple question about vtkPolyData


Hi, all
    I have a vtkPolyData, and I know it's composed of some polygons.
Now I want to get the point list of each polygon, how?
vtkPolyData::GetPolys()
seems helpful, but I don't know how to deal with a vtkCellArray which it
returns.
Please give me a solution. Thank you very much!

　　　　　　　　Dai Shuo
　　　　　　　　dai_shuocn at 163.com
　　　　　　　　　　2002-06-05



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