[vtk-developers] Creating a vtkPolyData from points and polygons

[Mikael Brudfors]

Hello,

 

I hope someone can help me with this very simple issue.

 

I have a surface stored in two double * as points and polygons (faces) which
I can access using moved_shape_ and get_faces_(). I would like to read this
into a vtkPolyData.

 

This is how I thought of doing it:

 

       vtkSmartPointer<vtkPoints> points =
vtkSmartPointer<vtkPoints>::New();

       for (int i = 0; i < model_->get_moved_shape_rows_(); i+=3)

       {

              double point[] = {model_->moved_shape_[i],
model_->moved_shape_[i+1], model_->moved_shape_[i+2]};

              points->InsertNextPoint(point);

       }

 

       vtkSmartPointer<vtkCellArray> polygons =
vtkSmartPointer<vtkCellArray>::New();

       for (int i = 0; i < model_->get_faces_rows_(); i+=3)

       {      

              vtkSmartPointer<vtkPolygon> polygon =
vtkSmartPointer<vtkPolygon>::New();

 

              polygon->GetPointIds()->SetNumberOfIds(3);

              polygon->GetPointIds()->SetId(model_->get_faces_()[i] - 1.0,
0);

              polygon->GetPointIds()->SetId(model_->get_faces_()[i + 1] -
1.0, 1);

              polygon->GetPointIds()->SetId(model_->get_faces_()[i + 2] -
1.0, 2);

 

              polygons->InsertNextCell(polygon);

       }

 

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

       polygonPolyData->SetPoints(points);

       polygonPolyData->SetPolys(polygons);

 

But it crashes at the line, polygons->InsertNextCell(polygon), at the first
iteration of the second for-loop. Seems like a memory allocation issue. 

 

Call stack:

 

>             msvcr100d.dll!_heap_alloc_base(unsigned __int64 size=84)  Line
55       C

               msvcr100d.dll!_heap_alloc_dbg_impl(unsigned __int64 nSize=32,
int nBlockUse=1, const char * szFileName=0x0000000000000000, int nLine=0,
int * errno_tmp=0x000000000012e910)  Line 431 + 0xa bytes        C++

               msvcr100d.dll!_nh_malloc_dbg_impl(unsigned __int64 nSize=32,
int nhFlag=0, int nBlockUse=1, const char * szFileName=0x0000000000000000,
int nLine=0, int * errno_tmp=0x000000000012e910)  Line 239 + 0x22 bytes
C++

               msvcr100d.dll!_nh_malloc_dbg(unsigned __int64 nSize=32, int
nhFlag=0, int nBlockUse=1, const char * szFileName=0x0000000000000000, int
nLine=0)  Line 302 + 0x2a bytes     C++

               msvcr100d.dll!_malloc_dbg(unsigned __int64 nSize=32, int
nBlockUse=1, const char * szFileName=0x0000000000000000, int nLine=0)  Line
160 + 0x22 bytes     C++

               msvcr100d.dll!realloc_help(void *
pUserData=0x0000000000000000, unsigned __int64 *
pnNewSize=0x000000000012ea68, int nBlockUse=1, const char *
szFileName=0x0000000000000000, int nLine=0, int fRealloc=1)  Line 705 + 0x21
bytes             C++

               msvcr100d.dll!_realloc_dbg(void *
pUserData=0x0000000000000000, unsigned __int64 nNewSize=32, int nBlockUse=1,
const char * szFileName=0x0000000000000000, int nLine=0)  Line 1040 + 0x29
bytes             C++

               msvcr100d.dll!realloc(void * pUserData=0x0000000000000000,
unsigned __int64 nNewSize=32)  Line 60 + 0x20 bytes          C++

 
vtkCommon.dll!vtkDataArrayTemplate<__int64>::ResizeAndExtend(__int64 sz=4)
Line 355 + 0x1e bytes                C++

 
vtkCommon.dll!vtkDataArrayTemplate<__int64>::WritePointer(__int64 id=0,
__int64 number=4)  Line 865 + 0xf bytes             C++

               vtkCommon.dll!vtkIdTypeArray::WritePointer(__int64 id=0,
__int64 number=4)  Line 129 + 0x3c bytes  C++

               vtkFiltering.dll!vtkCellArray::InsertNextCell(__int64 npts=3,
const __int64 * pts=0x00000000030c2420)  Line 249 + 0x1f bytes
C++

               vtkFiltering.dll!vtkCellArray::InsertNextCell(vtkCell *
cell=0x00000000030e2cc0)  Line 294              C++

 

Any help would be greatly appreciated!

 

Thank you,

 

Mikael

 

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