[Paraview] 2D and 1D vtkImageData::FindPoint() bug.

[Felipe Bordeu]

hi everybody,

I use the vtkImageData::findpoint(double x[3]) function to retrieve the 
id of a point.

in the case the data is 2D ( the dimension of z is 1) the spacing of the 
z in not relevant. Then if i put 0 in the spacing for z,  then the 
findpoint function fails to find the point.
After looking at the code, it became clear.

for know I can put a positive value into the z Spacing to bypass the bug.

this problem also happens for a 1D image data.


vtkImageData.cxx:706
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
vtkIdType vtkImageData::FindPoint(double x[3])
{
   int i, loc[3];
   double d;
   const double *origin = this->Origin;
   const double *spacing = this->Spacing;
   const int* extent = this->Extent;

   vtkIdType dims[3];
   dims[0] = extent[1] - extent[0] + 1;
   dims[1] = extent[3] - extent[2] + 1;
   dims[2] = extent[5] - extent[4] + 1;

   //
   //  Compute the ijk location
   //
   for (i=0; i<3; i++)
     {
     d = x[i] - origin[i];
     loc[i] = static_cast<int>((d / spacing[i]) + 0.5); <-------------- 
use of an irrelevant value
     if ( loc[i] < extent[i*2] || loc[i] > extent[i*2+1] )
       {
       return -1;
       }
     // since point id is relative to the first point actually stored
     loc[i] -= extent[i*2];
     }
   //
   //  From this location get the point id
   //
   return loc[2]*dims[0]*dims[1] + loc[1]*dims[0] + loc[0];

}

-- 

Felipe Bordeu Weldt
Ingénieur de Recherche
-------------------------------------
Tél. : 33 (0)2 40 37 16 57
Fax. : 33 (0)2 40 74 74 06
Felipe.Bordeu at ec-nantes.fr
Intitut GeM - UMR CNRS 6183
École Centrale Nantes
1 Rue de La Noë, 44321 Nantes, FRANCE
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