[vtkusers] surface from contours

[Simon ESNEAULT]

Hi,

We're facing the same problem here for the evaluation of a liver
segmentation algorithm. In order to reconstruct a surface from some manually
selected points, we've tried :
- vtkDelaunay3D : works very bad in our case
- vtkSurfaceReconstructionFilter : can reconstruct a surface from
unorganized points, but the result isn't very good in my opinion, some
points are ignored or moved ...
- vtkPowerCrustSurfaceReconstruction (not official find it here :
http://www.sq3.org.uk/powercrust/) gives better result, but it is still
buggy sometimes

- now we're using a home made solution following these steps :
        - spline interpolation for each contour
        - build a 2D binary image for each contour with 1 inside the spline,
and 0 outside
        - append all the 2D images
        - marchingcubes ...

But it is "de la cuisine"

Does anyone know a (vtk) way to build a surface from several 2D contours
(vtkParametricSpline in our case) ?
Thanks


On Wed, Apr 23, 2008 at 5:08 PM, Carsten Barkow <
carsten.barkow at googlemail.com> wrote:

> Hi,
>
> we've implemented a 3D segmentation algorithm and want to evaluate it. Due
> to this we get some manual segmented data, but those are only 2D contours
> for each section of the volume. So we want to generate a 3D surface from
> this contours.
> In VTK there are classes for this purpose like vtkVoxelContoursToSurface
> or vtkRuledSurfaceFilter. Unfortunately we can not make it show us a
> surface. Has anybody an idea where the fault is? Here is the code:
>
>   vtkPoints *points = vtkPoints::New();
>   vtkCellArray *cells = vtkCellArray::New();
>   int index = 0;
>   int temp;
>   VoxelXYZ v;
>   double x, y, z;
>   std::vector<VoxelXYZ> contour;
> // --- writing points and lines
> ----------------------------------------------------------------
>   for(int sec = 0; sec < borderPoints->getZRes(); ++sec){
>           if(borderPoints->getContour(sec, contour)){
>               //remember first point index of actual contour
>           temp = index;
>               for(std::vector<VoxelXYZ>::iterator it = contour.begin();
> it!=contour.end(); ++it){
>                   v = *it;
>                   x = static_cast<double>(v.getX());
>                   y = static_cast<double>(v.getY());
>                   z = static_cast<double>(v.getZ());
>                   points->InsertPoint(index, v.getX(), v.getY(),
> v.getZ());
>                   vtkLine *line = vtkLine::New();
>                   line->GetPointIds()->SetId(0, index);
>                   if((index-temp) == contour.size()-1)
>                         //reached last point of actual contour and close
> contour
>                         line->GetPointIds()->SetId(1, temp);
>                   else
>                        line->GetPointIds()->SetId(1, index+1);
>                   cells->InsertNextCell(line);
>                   line->Delete();
>                   ++index;
>              }
>         }
>   }
> //
> --------------------------------------------------------------------------------------------
>  // Insert points and cells
>   vtkPolyData *pointCloud = vtkPolyData::New();
>   pointCloud->SetPoints(points);
>   pointCloud->SetPolys(cells); // it also doesn't work with
> pointCloud->SetLines(cells);
>
> // --- just show contours for testing and this works fine we guess
> --------------------------------------
>   vtkPolyDataMapper *contourMapper = vtkPolyDataMapper::New();
>   contourMapper->SetInput(pointCloud);
>   vtkActor *contourActor = vtkActor::New();
>   contourActor->SetMapper(contourMapper);
>   contourActor->GetProperty()->SetColor(1, 0, 0);
>   contourActor->GetProperty()->SetAmbient(1);
>   contourActor->GetProperty()->SetDiffuse(0);
>   contourActor->GetProperty()->SetRepresentationToWireframe();
>   renSurface->AddActor(contourActor);
>   contourMapper->Delete();
>   contourActor->Delete();
> //
> ------------------------------------------------------------------------------------------------
>
> // vtkRuledSurfaceFilter approach
>   /*vtkRuledSurfaceFilter *ruledSurfaceFilter =
> vtkRuledSurfaceFilter::New();
>   ruledSurfaceFilter->SetInput(pointCloud);
>   ruledSurfaceFilter->CloseSurfaceOn();*/
>   // vtkVoxelContoursToSurfaceFilter approach
>   vtkVoxelContoursToSurfaceFilter *contourToSurfaceFilter =
> vtkVoxelContoursToSurfaceFilter::New();
>   contourToSuraceFilter->SetInput(pointCloud);
>       vtkPolyDataMapper *surfaceMapper = vtkPolyDataMapper::New();
>
> //surfaceMapper->SetInputConnection(ruledSurfaceFilter->GetOutputPort());
>
> surfaceMapper->SetInputConnection(contourToSurfaceFilter->GetOutputPort());
>     vtkActor *surfaceActor = vtkActor::New();
>   surfaceActor->SetMapper(surfaceMapper);
>   surfaceActor->GetProperty()->SetDiffuseColor(1.0000, 0.3882, 0.2784);
>   surfaceActor->GetProperty()->SetSpecularColor(1, 1, 1);
>   surfaceActor->GetProperty()->SetSpecular(.4);
>   surfaceActor->GetProperty()->SetSpecularPower(50);
>     renSurface->AddActor(surfaceActor);
>     points->Delete();
>   cells->Delete();
>   pointCloud->Delete();
>   surfaceMapper->Delete();
>   surfaceActor->Delete();
>   renSurface->Delete();
>
> ***thx for any hints/help***
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-- 
------------------------------------------------------------------
Simon Esneault
Laboratoire Traitement du Signal et de l'Image, (LTSI, UMR-INSERM 642)
Université de Rennes I, Campus de Beaulieu,
35042 Rennes Cedex, France.
Tel : +33 (0)6 64 61 30 94
Mail : simon.esneault at univ-rennes1.fr
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