MantisBT - VTK
'EvaluateFunction' line 81, as follows
"""
// Find the cell that contains xyz and get it
cell = this->DataSet->FindAndGetCell(x,NULL,-1,0.0,subId,pcoords,this->Weights);
^^^
"""
Note 4th parameter '0.0'. This is 'tol2' in API, which is used in
'vtkPointSet.cxx' in method 'FindCellWalk'
"""
double dist2;
if ( (cell->EvaluatePosition(x, closestPoint, subId,
pcoords, dist2, weights) == 1)
&& (dist2 <= tol2) )
{
return cellId;
}
"""
The problem is that 'tol2' is 0.0, but often 'dist2' may be calculated
to be approx 1e-032 to 1e-029, a very small number, but still greater
than 0.0! (NB: I adapted vtkPointSet.cxx to report 'dist2')
To fix this problem, when calling 'FindAndGetCell' in
'vtkImplicitDataSet' replace '0.0' with an appropriate small positive
tolerance value, e.g. '1e-16'. This could be user-configurable?
test_vtkImplicitDataSet_tol2_problem.py (2,732) 2011-07-03 21:44https://www.vtk.org/Bug/file/8970/test_vtkImplicitDataSet_tol2_problem.py